The median (IQR) percentage change in CD4 counts at 6 months among patients who developed a NNRTI-related skin rash was +190% (93%–576%, n = 219) compared with +119% (57%–272.5%, n = 2,512), p<0.0001 for those without skin rash and +250% (103%–724%, n = 229) versus +143% (71% to 325.5%, n = 2,471) p<0.0001, respectively at 12 months. The gene discussed is CD4; the disease is exanthem.