Fig 1: Cells resistant to xCT inhibition are sensitive to co-treatment with RSL3 and iFSP1.a, b Immunoblots of GPX4, FSP1, cystathionine ß-synthase (CBS), cystathionine ?-lyase (CSE), glutamate–cysteine ligase catalytic subunit (GCLC), glutamate–cysteine ligase modifier subunit (GCLM) in HT1080, HEK293T, A375, A549, HT29, MDA-MB-436, U-373, and UMRC2 cells (a), and HT1080, HEK293T, HLE, HLF, HepG2, and Huh7 cells (b). VCP was used as loading controls. c Cell viability of HT29, MDA-MB-436, U-373, and Huh7 cells treated with indicated concentrations of sulfasalazine, erastin, or RSL3 in the absence or presence of 5 µM iFSP1 for 24 h. Data are presented as mean ± s.d. of n = 3 wells of a 96-well plate from one representative of three independent experiments.