In most in vitro cell line models of childhood ALL, such as Jurkat and CCRF‐CEM, a common cause of GC‐therapy resistance is mutation/deletion of the NR3C1 gene (encoding GR), causing impaired receptor function (Powers et al, 1993; Hala et al, 1996; Schmidt et al, 2006). The gene discussed is NR3C1; the disease is acute lymphoblastic leukemia.