CD93 and neoplasm: Except for platelets showing the highest Cd93 mRNA expression, Cd93 mRNA level in p-pMCs was comparable to that in ECs, bone marrow cells and MLE-12 mouse alveolar epithelial cells, even in tumor ECs reported to overexpress CD93, whereas Ccl21a mRNA was most highly expressed in p-pMCs (Figure 3A).