Nonetheless, given that the risk genes of MND (ie, SOD1 and C9orf72) converge on similar functional pathways, including oxidative stress and neuroinflammation, as air pollution, there might be potential interactions between such risk genes and air pollution. As we did not have genotyping data for the controls in the present study, we encourage future studies to examine whether the link between air pollution and MND risk varies between individuals with or without risk genes. This evidence concerns the gene C9orf72 and mild neurocognitive disorder.