GPX4 and triple-negative breast carcinoma: Furthermore, in the triple-negative breast cancer cell line BT549, long-chain acyl-CoA synthetase 1(ACSL1) mediates the synthesis of α-tocopherol succinate (αESA, a representative polyunsaturated fatty acid) and induces ferroptosis in BT549 cells, which cannot be suppressed by GPX4 interference (85).