UBA1 and X-linked disease: To explore the mechanism of Bap31 on X-linked diseases, we identified 21 X-linked diseases-related proteins contained with 9 up-regulated (ABCB7, CCDC22, IGBP1, MAOA, MCTS1, MSN, PBDC1, PGK1, and SH3BGRL) and 12 down-regulated (HSD17B10, HUWE1, KIF4, MAGED1, PDHA1, PLXNA3, RBM3, SMS, TIMM17B, TSPAN7, UBA1, and VAP1) proteins from the iTRAQ results (Figures 1C–E and Supplementary Table S5).