ERBB2 and bladder transitional cell carcinoma: We chose two cell lines for analysis: the RT4 cells with the TACC3‐FGFR3 fusion as a less malignant luminal‐like BLCA (Luminal, L) and the 5637 cells with homozygous TP53 mutation and amplified ERBB2 as an aggressive and malignant human muscle‐invasive BLCA (Basal, B) (Figures 1B,C and 2, and Dataset S1).