Extended Data Fig. 9: Mammalian-specific genes may drive cell type specialization.

a, Phylogenetic tree illustrating the origin of the sfta2 gene from a duplication of the rhcg gene. b, Phylogenetic tree illustrating the origin of the scgb3a2 gene. c, Enrichment analysis of genes upregulated in the lungs of sfta2 knockout homozygous mice. The plot shows enriched GO terms, ReactomeDB pathways, and WikiPathways, with dot size indicating gene count and color representing significance.