In a study, Fiegenbaum et al. have shown a reduction of the T-T/A-T haplotype frequency (20%) in patients in whom myalgia developed during simvastatin treatment as compared with those who did not experienced ADR (41.4%), suggesting an association between ABCB1 gene variants and an increased susceptibility to myalgia [49]. The gene discussed is ABCB1; the disease is Myalgia.