Urothelial bladder cancer is a heterogeneous epithelial malignancy with multiple subtypes, each exhibiting distinct molecular patterns and morphological features.50 Our results showed that CST2, CST4, and CST6 were mainly expressed in infiltrated luminal tumors, whereas CST1 and CST3 showed no significant differences among subtypes. Here, CST2 is linked to bladder transitional cell carcinoma.