P2RY4 and liver cancer: Zhou et al. [68] found that 25 key genes of Emodin in the treatment of liver cancer are mainly enriched in the inflammatory response, neuropeptide signaling pathway and positive regulation of cytoplasmic calcium ion concentration, etc. In addition, GPR68, SSTR5, C5, LPAR6, P2RY4, and other targets may participate in the molecular mechanism of Emodin in the treatment of liver cancer and finally exert the effect of inhibiting liver cancer.