The results revealed that a one standard deviation (1-SD) increase in the MFI of CD16–CD56+ on NK cells was associated with a lower risk of ALS in both the IVW method (odds ratio [OR] = 0.966, 95% confidence interval [CI] = 0.946–0.987, P = 0.002) and MR-Egger (OR = 0.934, 95% CI = 0.893–0.976, P = 0.005; Figure 3). The gene discussed is NCAM1; the disease is amyotrophic lateral sclerosis.