As we mentioned above in the “EMT section”, this miRNA is associated with mutant p53 expression and also is correlated with EMT and migration in breast cancer cells (Figure 5B); however, under ionizing radiotherapy miR-155 favour an apoptotic outcome by targeting RAD51 (Gasparini et al., 2014), which is a critical factor for the DNA repair thorugh homologous recombination. This evidence concerns the gene TP53 and breast cancer.