RB1 and neuroendocrine carcinoma: In contrast to NEC, TP53 and RB1 alterations are absent or exceedingly rare in extramammary NET (including G3 NET)12,45–49, which instead have mutations in chromatin remodeling genes MEN1 (lung and pancreas), DAXX/ATRX (pancreas), the mTOR pathway (pancreas), and CDNK1B (small intestine)45–51.