For example, miR-143-3p inhibits the tumorigenesis of pancreatic ductal adenocarcinoma by targeting KRAS (Xie et al., 2019); MiR-143-3p targets MAPK7 to inhibit the proliferation, migration, and invasion of osteosarcoma cells (Hou et al., 2019); LINC00667/miR-143-3p regulates RRM2 to affect the progression of small-cell lung cancer cells (Yang et al., 2019). The gene discussed is RRM2; the disease is small cell lung carcinoma.