SLC31A1 and fibrosarcoma: Eventually, according to the data, for example, ferric ammonium citrate (FAC) exhibits cytotoxic effects on HT-1080 fibrosarcoma cells only at concentrations ≥5 mM in vitro [73], but in HEK293T cells overexpressing solute carrier family 31 member 1 (SLC31A1), a concentration of 10–20 μM was sufficient to induce cuproptosis in the majority of cells, with a significant decrease in viability approaching 0 [5].