In terms of renal cell carcinoma (RCC), clinical experimental studies have proven that some KLKs, such as KLK1, KLK3, KLK6, KLK7, and KLK15, are differentially expressed in different subtypes of RCC, and KLK6 has predictive value in RCC [7, 8]. Here, KLK6 is linked to renal cell carcinoma.