Three isoforms of nitric oxide synthase (NOS), inducible NOS (iNOS), endothelial NOS (eNOS), and neuronal NOS (nNOS), have been detected in a variety of human cancers (Kim and Thomas, 2022; Ramírez-Patiño et al., 2022; Sahebnasagh et al., 2022). Here, NOS2 is linked to cancer.