PKM and nonpapillary renal cell carcinoma: Although some renal carcinoma-related biomarkers have been released recently, such as Li et al. [6] have developed a classification system of ccRCC based on PKM alternative splicing; Caliskan et al. [7] conducted comparative analysis of RNA-seq transcriptome data of different RCC subtypes and found reporter molecules that were specific to each other or subtype; there are still few markers or models that can be used to predict the prognosis of ccRCC patients clinically.