RAD51 and acute myeloid leukemia: However, there are several studies on other genes that are required for homologous recombination repair, i.e. RAD51, XRCC2 and XRCC3. The RAD51-135 (G/C) variant allele has been associated with increased risk of AML and this relation was most pronounced for AML associated with a previous history of treatment with chemo- or radiotherapy [26-29].