ATXN1 and Parkinson disease: Addressing the cancer risk in patients with Parkinson’s disease, being a drinker (P = 0.004; AIC = 349.8) seemed to be a risk factor for the cancer comorbidity in patients with Parkinson’s disease, which was a result also reported previously by our group.20 Considering the three candidate genes, the best logistic model (P = 0.041; AIC = 909.93) was found for the ATXN1 gene, which showed a statistically significant prediction value of the quadratic term for the long allele [P = 0.0491, OR (95% CI): 1.002 (1.00–1.004)] in modifying cancer risk among patients with Parkinson’s disease (Fig. 3).