The document discusses the lung microbiome and remaining challenges in the field. It notes that culture-independent techniques have improved understanding of microbes living in contact with the body. The lung was found to not be sterile as previously believed. Understanding the lung microbiome's relationship with respiratory surfaces is a promising area. However, standardizing sampling and analyzing the microbiome present additional complexity. Several challenges remain such as harmonizing genomic methods, characterizing the microbiome's functions, and improving epidemiological studies with longitudinal patient data. Addressing these challenges will provide insights into how the lung microbiome impacts disease pathogenesis and can be managed.