FANCD2 and Friedreich ataxia: Interestingly, CAL27-c34 and CAL33-c11 clones did not ubiquitinate FANCD2 (Figure 3A), and neither showed nuclear foci upon DNA damage (Figure 3B,C), suggesting a defective FA pathway similar to FA-HNSCC cells VU1365 (Figure 3B,C) [20] or blood cells and fibroblasts from FA patients.