As bladder tumors of the basal subtype are less likely to respond to the anti-PD-L1 antibody atezolizumab4, we hypothesized that bladder cancers with mixed histology and regions of squamous differentiation may be intrinsically resistant to immunotherapy due to the presence of a pre-existent treatment-resistant population of cancer cells. The gene discussed is CD274; the disease is urinary bladder carcinoma.