CD81 and Marchiafava-Bignami disease: Based on their function, 9 of them modulate cell cycle (CCND1, HGF, LAMP5, EDNRB, DUSP4, IFI6, MT1F, PURPL and TGFBI) (33–41), 7 of them are involved in cell-cell interactions and signaling (ST3GAL6, TSPAN7, VCAM1, PTPRC, CD19, CD27 and CD81) (42–48), 3 of them contribute to myeloma bone disease (MBD) (DKK1, CCL3 and CXCL12) (49–51), 2 of them promote angiogenesis (ADM and NDNF) (52, 53) and 7 of them are of unknown functional role (PRDM5, BTBD3, PRR15, LINC01480, IFITM1, LINC01239 and GADD45A).