Accordingly, the patient, PDX, and UCDCaP cells contained mutations in critical genes such as AR (missense, deletion), ATM, BRCA1, CHD4, ERBB2, PIK3CA, TMPRSS2, TP53, TSC1/2, and XPA (frameshift) (Supplementary Fig. 1b), again underscoring the relevance and fidelity of the UCDCaP cell line model in preserving the genetic landscape of the original patient tumor. This evidence concerns the gene ERBB2 and neoplasm.