PRDM1 and neoplasm: Notably, suppression of PRDM1 attenuated mitogenic extracellular signal-regulated kinase (ERK) 1 and 2 phosphorylation in the tumor mass, whereas levels of pro-apoptotic p53 and growth/differentiation factor 15 (Gdf15), a representative target of p53 signal, were elevated (Fig. 2a).