This incomplete selection of cancer risk studies in PD, despite having deviating results, showed a general decrease in many smoking and non-smoking-related cancers in PD patients compared to controls, and a general increase in melanomas and brain tumors, and in some studies, an increase in breast, kidney and other tumors, and a general increase in LRRK2 carriers (see Table 2). This evidence concerns the gene LRRK2 and melanoma.