Firstly, we examined the KRT7 expression in bladder tumors on the webserver of The Human Protein Atlas (https://www.proteinatlas.org/) and found that KRT7 protein was highly expressed in the low-grade bladder cancer cells but medially or lowly expressed in high-grade bladder cancer cells (Supplementary Figure 2). Here, KRT7 is linked to urinary bladder carcinoma.