RAD51 and neoplasm: CHK2 provides a survival signal for tumor cells when exposed to DNA damaging agents [15], especially for those inducing DSB, like doxorubicin, cisplatin [16], oxaliplatin and 5FU [17, 18] and is a key protein for DNA repair mediating BRCA2 phosphorilation that leads to disruption of RAD51-BRCA2 complex and then DSB repair.