SLC12A2 and bladder transitional cell carcinoma: NKCC1 expression was found as a significant prognostic biomarker in BLCA (OS, p = 0.0138; PFS, p = 0.0577), CESC (OS, p = 0.0137; PFS, p = 0.009), and KIRC (OS, p < 0.0001; PFS, p < 0.0001).