In particular, reduced RAD51 expression correlated with increased expression of genes that inhibit metastatic invasion, including; CCL7, BRMS1, NME4 and TIMP3, and a corresponding decrease in expression of genes promoting metastatic invasion and proliferation; MMP13, MMP11, MMP10, MMP3, MMP7, MTA1, IL1β, TCF20, and oncogenes H-RAS, K-RAS, MDM2 and the mutated form of TP53. Four (namely, MMP2, MET, NF2 and TP53) of the 25 identified genes are expressed in aggressive lung metastases from breast cancer [20]. This evidence concerns the gene IL1B and breast cancer.