In this study, Liu et al. identified a subpopulation of pathogenic macrophages, referred to as Toe-Macs, which are characterized by overexpression of the DNA demethylase TET3 in metabolic dysfunction–associated steatohepatitis (MASH), non–small cell lung cancer (NSCLC), and endometriosis. Here, TET3 is linked to non-small cell lung carcinoma.