J. MEFs expressing hNCOA4-TurboID were treated with 10 μg/ml FAC for 3 h (indicated as F) or 100 μM DFO for 3 h after treatment with 10 μg/ml FAC for 12 h (indicated as D), and then cultured with DMSO or 50 μM biotin for 30 min. Triton-soluble cell lysates were pulled down by streptavidin beads. Inputs and pulldown samples were analyzed by immunoblotting with the indicated antibodies. The black and white arrowheads indicate hNCOA4-TurboID and endogenous NCOA4, respectively. 