IL5RA and Miyoshi myopathy: Mendelian randomization analysis incorporating a Steiger test for directionality supported a causal relationship between increased levels of B-cell maturation antigen (BCMA; PIVW = 5.6 × 10−6) and interleukin-5 receptor subunit alpha (IL5RA; PIVW = 9.0 × 10−13) and increased MM risk (Fig. 3c-d).