PPP1R13L and melanoma: N-terminal phosphorylation of iASPP retards its migration in sodium dodecyl sulfate (SDS) gel and causes nuclear accumulation in cells,25 and nuclear iASPP localisation is associated with human melanoma metastasis.25 The observation that nuclear iASPP is enriched in PCa cells with invasive properties led us to test the hypothesis that iASPP phosphorylation may be enhanced in metastatic PCa cells in vitro using a pair of isogenic LNCaP cell lines.