GSTK1 and bladder transitional cell carcinoma: The Kaplan–Meier plotter and HPA databases indicated that, although survival results showed that low GSTK1 expression was significantly related to poor survival in BLCA, KIRP, and HNSC, only in patients with HNSC was the expression level of GSTK1 protein decreased in the tumor compared with the normal tissues around it.