Notably, enhanced tumor angiogenesis and tumor mobilization of MDSCs were observed with weekly gemcitabine alone treatment, which was associated with increased expression of prokineticin 2 (PK2 or Bv8, a factor involved in MDSCs differentiation and mobilization) compared to MC gemcitabine or the combination of these regimens [45]. This evidence concerns the gene PROK2 and neoplasm.