GSTM1 and amyotrophic lateral sclerosis: Moreover, the findings from the multivariable MR analysis revealed that confounding variables such as blood pressure, LDL‐C, total cholesterol levels, BMI, and smoking do not play a role in the causal relationships between Hb and ALS, despite the connections of these factors to both Hb and ALS indicated in previous studies (Hämäläinen et al.