FKBP4 and melanoma: The four hub mRNAs (FKBP4, RCC1, GBP1, and PRADC1), one miRNA (hsa-mir-137), and seven lncRNAs (HCP5, SNHG14, FGD5-AS1, HCG18, MAGI2-AS3, OIP5-AS1, and TUG1) in ceRNA network play important roles in the development of melanoma and other various tumors and are widely involved in the immune regulation process.