CCL2 and neoplasm: Similarly, particular proteins present in the secretome of HUCPVCs (Table 1), such as C-C motif chemokine 2 (CCL2), platelet-derived growth factor C (PDGF-C), semaphorin-7A (Sema-7A), periostin, and interleukin 6 (IL-6) are known to be important regulators of homeostasis in a variety of physiological conditions, but have also been described to influence tumor cell behavior, as is the case of a classic proto-oncogene [99–121].