KCNJ2 and sarcopenia: Given that reductions in ALM and HGS are common features of sarcopenia [6,7], these 10 shared genes exhibited consistent causal effects: 5 genes (RXRA, MDM1, RBL2, KCNJ2, ADHFE1) were positive for sarcopenia and negative for ALM and HGS, while 5 genes (NMB, TECPR2, MGAT3, ECHDC2, GINM1) were negative for sarcopenia and positive for ALM and HGS (Figure 4a–c).