Chronic lymphocytic leukemia deletion gene 7(CLLD7) orRCC1 and BTB domain-containing protein 1(RCBTB1) andchromosome condensation 1-like(CHC1L) orRCC1 and BTB domain-containing protein 2(RCBTB2) are potential tumor suppressor genes located at 13q14.3 telomeric toRB1. This evidence concerns the gene RCBTB1 and lymphoid leukemia.