Whether IMA exhibited NKX2‐1/TTF‐1 exon 1 expression was further validated using qPCR, revealing that 19 of 20 (95%) cases exhibited higher exon 1 expression relative to that of exon 4/5, compared to EGFR‐mutated adenocarcinoma that was immunohistochemically positive for TTF‐1 (Figure 4B). Here, TTF1 is linked to adenocarcinoma.