NKX2-1 and adenocarcinoma: For instance, Chua et al. reported 27% (4 out of 15) EGFR-mutant T790M-tumors exhibited widespread loss of adenocarcinoma lineage markers such as NAPSA, NKX2-1, SFTA2, and SFTA3, and increased expression of squamous or neuroendocrine marker genes, despite retaining adenocarcinoma morphology [38].