Combining HLA-DQB1 with HLA-B epitope testing increased the sensitivity for CIA prediction to 41% (CI 95%: 31–51%) and showed a 30% reduction in the lower risk group (a reduction in CIA incidence from 0.7% to <0.5%), which approximates the agranulocytosis risk of other antipsychotics [6]. Here, HLA-DQB1 is linked to Absence of circulating granulocytes.