In the tumoral microenvironment, tumor cells express iNOS, eNOS, and nNOS, depending on tumor type and stage, endothelial cells express eNOS and iNOS whereas tumor-associated stromal fibroblasts and immune cells express iNOS (Fukumura et al., 2006; Monteiro et al., 2015; López-Sánchez et al., 2019). Here, NOS1 is linked to neoplasm.