A recent study found that cinobufotalin injection promotes the enrichment of lymphocyte with CD3+, CD4+, and CD8+ in cancer and adjacent tissues and activates the proopiomelanocortin/β-endorphin/μ-opioid receptor pathway by promoting the proliferation of immune cells to alleviate cancer pain and increase pain threshold in mice [39]. The gene discussed is POMC; the disease is cancer.