RB1 and neuroendocrine carcinoma: NETs may occur sporadically or in association with syndromes like Von Hippel-Lindau or MEN1, with genetic alterations varying by subtype such as MEN1, DAXX, ATRX in well-differentiated NETs and TP53, RB1 in neuroendocrine carcinomas [NECs] [5,6,10].