PTN and hepatocellular carcinoma: MiR-371a-5p is a component of the pathway, including lymphoid enhancer-binding factor 1/SRC kinase signaling inhibitor 1/pleiotrophin/snail family transcriptional repressor 2 (LEF-1/SRCIN1/PTN/Slug), cause of which testosterone induces an upregulation of miR-371a-5p leading to proliferation, neoangiogenesis and metastasis of HCC, especially in men.