GSTM1 and Haim-Munk syndrome: Although these variants have been associated with a higher risk of leukemia development (Li et al. 2018), there are conflicting reports on the association of the GSTM1-null and GSTT1-null variants with relapse in patients with HMs (Balta et al. 2003; Franca et al. 2012; Stanulla et al. 2000; Takanashi et al. 2003).