A look at Alector's core values - this is how we operate, engage with one another, and show up day to day.

1. Our
Values

2. Our values are our NorthStar.
They guide how we behave as individuals and as teams, to relentlessly pursue
solutions to human health problems that were—until now—unsolvable. Living these
values is an important part of thriving at Alector. They are our code of ethics, and a
foundation for decision-making. Putting them into practice every day allows us to
move forward, together, in the rightdirection.
Bringing our values to life

3. Our Values
Own it—
with the freedom
to figure it out.

4. Value 1
Own it—
with the freedom
to figure itout.
We are here to stop
neurodegenerative disease
and cancer through innate
immuno-biology.
This audacious goal requires
relentless determination and
personal initiative from each of
us, every day. Our all-hands-on-
deck mentality means there are
no unglamorous tasks atAlector
—all efforts that advance our
important work are vital. Great
things are possible when great
thinkers have the autonomy to
explore and implement.

5. Opportunities to cheer each other
on, in the lab or on the court, keep
us inspired and connected as a
team.
Arjun understands the importance of
camaraderie—and fun—let’s not
forget fun. He pitched the idea of an
Alector mascot to the whole
company, held a naming
competition and, voila— Alexander
“Alec” Mammalton was born. As
was our intranet: Hippocampus.
Hippo (we’re focused on the hippocampus part of
the brain) + camp (we work hard but don’t take
ourselves too seriously) + us (we’re in it together)
Own it—with the freedom to figure it out. Arjun Sandhu, Senior Research Associate

6. Our Values
Never give up—
persevere
and forge
a new path.

7. Value 2
Never give up—
persevere and forge
a new path.
To bring life-changing therapies
to patients, there's still much
for us to discover about the
immune system.
Persistence is built into our DNA
at Alector, as is our ability to flex
and respond rapidly if new facts
indicate a change of course.
Maintaining resilience in the face
of adversity requires that westay
nimble, proactive, and ever-
optimistic in the pursuit of our
goals.

8. We were having major issues with
with an important assay on a primary
program. Our drug interfered with all
of the assays that had been
developed up to that point. Cheryl
took on the huge, painstaking project
of developing a new approach,
which paid off, because she found a
‘unicorn antibody’. Thanks to her
tenacity, she discovered a very rare
pairing of antibodies for the assay
that allowed us to have an assay for
cerebrospinal fluid.
Cheryl Barner, Senior Associate Scientist
Never give up—persevere and forge a new path.

9. Dominik’s can-do attitude is
coming in handy during the
COVID-19 disruptions. As an
engaged parent working from
home, he’s had to meet some big
challenges, including training
himself on tasks he hasn’t
tackled before, coming up with
new protocols that we didn’t
previously have expertise for in-
house—while providing childcare
for his daughter. Perseverance,
personified.
Never give up—persevere and forge a new path. Dominik Haddad, Senior Scientist

10. Our Values
Question
convention—
with the courage
to challenge
assumptions.

11. Value 3
Question convention—
with the courage to
challenge assumptions.
Cures come fromcuriosity.
In science, we don’t oftenknow
where the signal is until we see
it. So we ask questions to push
the boundaries of what’s
possible. We must rebel against
human nature—defaulting to
what’s comfortable—and
continually embrace informed
risk.

12. Last year, we were moving fast
… researchers didn’t feel that
their voices were being heard,
and it was affecting morale.
Shalu went straight to Arnon,
addressed her concerns, and
now, researchers have a
dedicated rotating
representative on our
executive leadership team.
Question convention—
with the courage to
challenge assumptions. Shalu Srinivasan, Staff Scientist

13. For 30 years, the consensus believed
that neurodegeneration was caused by
the accumulation of misfolded proteins
(the “amyloid hypothesis”). They
believed that if you developed drugs
that targeted these proteins, you could
treat the condition. Arnon contested this
consensus (one of his superpowers),
and changed his — and Alector’s —
focus to the innate immune system,
with the idea that it could counteract
multiple pathologies. Had he not
challenged the status quo, we wouldn’t
be entering phase 2 clinical trials.
Arnon Rosenthal, Co-Founder & CEO
Question convention—with the courage to challenge assumptions.

14. Our Values
Embrace
feedback—
and a growth
mindset.

15. Value 4
Embrace feedback—
and a growth mindset.
We're a data-driven company,
so valuing feedback in all its
forms is oursuperpower.
Be it scientific, clinical,
or interpersonal, feedback
propels us forward. We must get
really good at giving feedbackas
well as welcoming it, acting on it,
and learning from it. Otherwise,
we'll stagnate. Always engage
with honesty and thebest
of intentions.

16. Our COVID task force has taken
multiple pulse-checks during the
pandemic to see how we can best
support our team.
Some people asked for a work-from-
home ergonomics stipend. (Done.)
Others needed more dedicated
heads-down time, so we instituted
‘Deep Work Thursdays” without
morning meetings. (Done.)
A few wanted to be back on site
because they felt extremely
unproductive at home. (Done.)
We hear you. We’re here for you.
Embrace feedback—and a growth mindset.
Carlos Lorenzana Charles Wolfus Clare Hunt Daniel Maslyar
David Oh Jignya Patel Lauren Cheney
Robert King Shehnaaz Suliman Spencer Liang Tina Schwabe

17. Our Values
Elevate
each other—
all wins are
shared wins.

18. Value 5
Elevate
each other—
all wins are
shared wins.
Lone wolves don’t develop
drugs and buildcompanies—
teams do.
Our success hinges upon our
ability to collaborate and
celebrate each other’sstrengths.
Each of us shares responsibility
for our outcomes as an
organization—both the wins and
the weak spots. We’re in this
together.

19. There’s no one who gives of their
time more generously than Maddy.
She’s the first to step up to onboard
new team members, and share
everything she knows about
projects, so they can gain historical
context and ramp up quickly. She’s
been described as ‘the glue for
clinical ops’ by her peers, and is a
champion of cross-functional
collaboration. The clinical operations
team has doubled in size this year,
and Maddy has helped this growing
team be successful.
Elevate each other—all wins are shared wins. Maddy Spencer, Clinical Trial Manager, Clinical Operations