In high L-arginine-dependent tumors, such as breast cancer (Abdelmagid et al., 2011), CRC (Lu et al., 2013), and HCC (Kishikawa et al., 2015), increased expression of the transporter CAT-1 (SLC7A1) has been observed, and CAT-1 (SLC7A1) knockdown decreases the viability of cancer cells and induces apoptosis. The gene discussed is SLC7A1; the disease is colorectal carcinoma.