Indeed, the expression level of Gab1 was found to be weaker in normal urothelial cell lines (E6, normal) and low-grade urothelial carcinoma cell lines (RT4, Grade I; TSGH8301, Grade II) and higher in high-grade urothelial carcinoma cell lines (J82, T24, Grade III) (Figure S1A). Here, GAB1 is linked to urothelial carcinoma.