However, in some tumor cell lines, such as 143B osteosarcoma cells, loss of SLC1A5 did not suppress tumor growth, but instead elicit an amino acid starvation response and up-regulation of SLC38A1, indicating that SLC38A1 may act as a rescue transporter when SLC1A5 is blocked [40]. Here, SLC1A5 is linked to osteosarcoma.