NOS2 and colorectal cancer: In addition to DLD-1 cells, variable levels of inducible nitric oxide synthase (iNOS) expression have been documented across several other human colorectal cancer (CRC) cell lines, including HT-29, HCT116, and SW480 (Ambs et al., 1998; Kobelt et al., 2020; Du et al., 2023).