Tests for interaction were found non-significant for subgroups of different study design; adjustment for PSA; adjustment for BMI and ALS; and time frame of Bonovas et al. analysis (pinteraction = 0.45, 0.76, 0.24 and 0.63, respectively).This confirmed the robustness of the results. This evidence concerns the gene KLK3 and amyotrophic lateral sclerosis.