IHC staining in both tumors demonstrated strong positivity for at least one of the neuroendocrine markers (CgA, SYN, CD56, NSE) in more than 80% of tumor cells and at least one of the squamous differentiation markers (P40, P63, CK5/6) in more than 95% of tumor cells (Figure 1B). This evidence concerns the gene KRT5 and neoplasm.