The basal (Supplementary Figure S10) PORlo bladder cancer cell lines T24 and SCaBER were used as in vitro models of POR suppression in MIBC (Figures 6A and 6C) and showed no/low inducible CYP1 enzyme activity, respectively (Figure 6D) despite CYP1A1 and CYP1B1 transcripts being ITE‐inducible (Supplementary Figure S11). Here, CYP1B1 is linked to urinary bladder carcinoma.