SIK2 and Friedreich ataxia: Consistent with these findings, western blot analysis of whole cell lysates prepared from two FA patient‐derived FANCA−/− fibroblasts vs isogenic FANCA‐complemented fibroblasts revealed reduced levels of SIK2 pS358 in FANCA‐deficient cells, while total SIK2 levels were unaffected by FANCA status (Fig. 6F).