CHEK1 and triple-negative breast carcinoma: Similarly, a trans-species genetic screen by Bennett et al.[53] identified two ribonucleotide reductase genes (RRM1 and RRM2) and a checkpoint kinase (CHK1) as potential targets for triple-negative breast cancer patients, which they validated in both species with drug treatment experiments using TgC3(1)-Tag and human xenograft tumors.