PROK2 and neoplasm: They are reprogrammed both metabolically and to express high levels of pro-angiogenic and pro-invasive factors such as S100a8, S100a9, MMP8, MMP9, Bv8/Prok2 and vascular endothelial growth factor (Vegfa). Thus, tumor-associated neutrophils (TANs) could promote the migration, invasiveness, and extravasation of tumor cells (Figure 2A).