LncRNA CASC9 is a widely studied lncRNA in cancer, and it is a common oncogene that can promote the growth and proliferation of cancer cells in esophageal cancer, oral cancer, rectal cancer, breast cancer, and so on (Pan et al., 2016; Liang et al., 2018; Luo et al., 2019). The gene discussed is CASC9; the disease is breast cancer.