ERBB2 and neoplasm: Despite a similar somatic mutation burden and tumor purity among mucinous cancers (Supplementary Fig. S1), higher mutation frequencies were observed in ovarian mucinous compared with GI mucinous carcinomas in four of the six genes frequently mutated in these tumors, including CDKN2A [posterior mean LOR (LOR ̄ = 1.87; 90% CI, 0.51–3.58)], TP53 (LOR ̄ = 0.42; 90% CI, −0.38 to 1.33), KRAS (LOR ̄ = 0.49; 90% CI, −0.28 to 1.43), and ERBB2 (LOR ̄ = 2.11; 90% CI, 0.27–4.62).