PTEN and melanoma: These findings suggest that the inhibition of cell growth resulting from knockdown of miR-19b in melanoma cells is independent of PI3K signaling pathway regulation by PTEN. Therefore, miR-19b mediated hTERT activation through the targeting of PITX1 may involve another oncogenesis pathway such as NF-κB or the Wnt signaling pathway, which can be activated by hTERT expression in melanoma cells.