Conversely, MSC can contribute to tumor progression by secretion of tumor-supportive immunosuppressive factors, inhibition of antitumor immune response, and promotion of angiogenesis by increasing pro-angiogenic factors, such as MIP-2, VEGF, TGF-β, and IL-6, which shows their very controversial role in this research field [30]. This evidence concerns the gene IL6 and neoplasm.