Here, we review the literature on the pleiotropic activities and functions of RKIP and include: (i) RKIP structure, (ii) RKIP functions on cell signaling, (iii) regulation of RKIP expression, (iv) RKIP expression and tumor growth and resistance, (v) RKIP–immune system cross-talks in cancer and inflammatory diseases, (vi) bioinformatic analyses of RKIP expression levels and immune cells, and (vii) RKIP expression in cancer and inflammatory diseases [20,21]. This evidence concerns the gene PEBP1 and cancer.