This study investigated the internalization of wild-type and mutant forms of the VSV-G protein in cells. The researchers mutated basic amino acids in the cytoplasmic tail of VSV-G to neutral amino acids to see if this affected internalization. They found that lower expressing cells internalized wild-type VSV-G faster, and that wild-type and mutant VSV-G were expressed at the same level on the plasma membrane but the mutant was expressed at a significantly lower level within cells overall. Further studies are needed to understand why and investigate if mutant VSV-G transport or degradation is impaired.