HOXC9 and breast cancer: For instance, researchers synthesized the new molecule 5H-pyrido[3,2-a] phenoxazine-5-one in the laboratory, evaluated its ability to regulate the activity of lncRNA HOTAIR and HOXC locus genes from HOXC9 to HOXC13 in MCF-7 human breast cancer cell lines, and confirmed that 5H-pyrido[3,2-a] phenoxazine-5-one was able to inhibit the relevant HOX gene expression and counteract the pathogenesis of breast cancer (172).