(2) ABCB5 expression has been shown to be higher in more advanced stages of cancer, metastasis, and refractory tumors when examined by immunohistochemistry or RT-qPCR in patients with colorectal cancer, oral squamous cell carcinoma, leukemia, and breast cancer[40,46,61,63]. The gene discussed is ABCB5; the disease is oral cavity squamous cell carcinoma.