PIWIL1 and hepatocellular carcinoma: C3 secretion induced by Piwi Like RNA-Mediated Gene Silencing 1 protein (PIWIL1) in human hepatocellular carcinoma (HCC) cells leads to the activation of p38 and MAPK signalling in MDSCs, which, in turn, triggers the expression of immunosuppressive cytokine IL-10 in these cells (83).