PEBP1 and neoplasm: Additionally, it is documented that loss of RKIP expression is not due to the promoter methylation, and some in vitro and in vivo studies have shown its importance in the modulation of cellular growth [31, 32], motility [33, 34], epithelial to mesenchymal transition (EMT) [35], differentiation [36], invasion, and tumor metastasis [23, 37].