To understand the biased prevalence of tuft cell-like tumors among histotypes (SCLC ≥ LCNEC ≫ SQCC, and absence in adenocarcinoma), we examined the expression of a marker of squamous differentiation (CK5) and a common marker of neuroendocrine tumors (CD56) [28]. This evidence concerns the gene KRT5 and adenocarcinoma.