SNHG21 and prostate cancer: To identify the prognosis-related SNHGs in prostate cancer, we first explored the expression data of the SNHG family (SNHG1, SNHG2/GAS5, SNHG3, SNHG4, SNHG5, SNHG6, SNHG7, SNHG8, SNHG9, SNHG10, SNHG11, SNHG12, SNHG13/DANCR, SNHG14, SNHG15, SNHG16, SNHG17, SNHG18, SNHG19, SNHG20, SNHG21, SNHG22, SNHG23/24/MEG8, SNHG25, SNHG26, SNGH27, SNHG28, SNHG29, SNHG30, SNHG31, and SNHG32) in the PRAD cohort from TCGA database.