Like CD31, CD34 has been proposed as a sensitive marker for endothelial cells [22], has been used to diagnose vascular tumors [26], and has been used to evaluate the degree of angiogenesis in a variety of neoplasms, including cervical cancer, prostate cancer, and multiple myeloma [22, 27, 28]. The gene discussed is PECAM1; the disease is plasma cell myeloma.