HDAC6 and neoplasm: Here, we show that EGF stimulation induces PKCε-dependent phosphorylation of migration and invasion inhibitory protein (MIIP) at Ser303; this phosphorylation promotes the interaction between MIIP and RelA in the nucleus, by which MIIP prevents histone deacetylase 6 (HDAC6)-mediated RelA deacetylation, and thus enhances transcriptional activity of RelA and facilitates tumor metastasis.