RAD51 and non-small cell lung carcinoma: In NSCLC, Tsai et al. reported that down-regulation of Rad51 using specific Rad51 small interfering RNA significantly increased cytotoxicity.36 Chan et al. 37 reported that down-regulation of Rad51 decreased homologous recombination, and increased sensitivity to the DNA cross-linking agents mitomycin C and cisplatin.