Hancock et al. screened 1065 patients with PD for NOS1, NOS2A, and NOS3 SNVs, showing they increase the risk of the disease (see Section 2.3.3 and Section 2.4.4 on “Parkinson’s Disease” regarding NOS2 and NOS3), as well as the gene interaction with the environment (cigarette smoking, use of caffeine, nonsteroidal anti-inflammatory drugs, and pesticides). Here, NOS1 is linked to Parkinson disease.