Similar to the above results, hRNase 1 knockout KPL4 (KO-R1) cells generated by CRISPR-Cas9 exhibited reduced ALDH1 activity (Fig. 2l, m), further supporting a positive role of hRNase 1 in the stem-like properties and tumor initiation in breast cancer. The gene discussed is ALDH1A1; the disease is breast carcinoma.