Inhibition of JNK enhances survival of Fancc^−/− progenitors treated with TNF-α. (A) JNK inhibitor and progenitor assays. WT and Fancc^−/− low-density MNCs were cultured in colony assays with either JNK III or a DMSO control in the presence or absence of 10 ng/mL TNF-α. Data are shown as a percentage of untreated control conditions where no TNF-α was added; n = 3 mice/genotype. *P < .01; **P < .002. (B) TNF-α–induced apoptosis in c-kit⁺ cells. WT and Fancc^−/− c-kit⁺ cells were either pretreated with JNK III or a DMSO control before a 24-hour exposure to 10 ng/mL TNF-α. Cytospins of cells from each experimental group were made before analyzing apoptosis using a TUNEL assay; n = 3. *P < .03.