PRL and amyotrophic lateral sclerosis: Further analysis adjusting for smoking-related factors revealed consistent trends: after adjusting for smoking status (Table E in S1 Text), PRL was associated with a decreased risk of ALS (per SD increase HR [95% CI] = 0.81 [0.71, 0.93]; p = 0.008), while RPE was linked to an increased risk (per SD increase HR [95% CI] = 1.20 [1.07, 1.35]; p = 0.002).