RB1 and hepatocellular carcinoma: RIZ, retinoblastoma protein (Rb)-interacting zinc-finger gene (PRDM2), was isolated during functional screening for Rb-binding proteins (Buyse et al, 1995) and was mapped to 1p36.2; the RIZ locus is a target of frequent deletion in hepatocellular carcinoma (Fang et al, 2000).