ERBB3 and breast carcinoma: We selected the five most frequent tumor types in the ERBB2mut tumor cohort—NSCLC, breast cancer, CRC, bladder cancer, and GEC—as the subject of more focused analysis throughout the remainder of the study (Fig. 1C), with the exception of ERBB3 mutation–specific analyses for which we focused on the most frequent tumor types in the ERBB3-mutated (ERBB3mut) tumor cohort (CRC, breast, bladder, GEC, and uterine cancers).