Molecular biology-based methods of diagnosis that detect specific mutations are required to confirm G6PD deficiency, particularly in women as well as in men with unexpected intermediate results (e.g., samples of men with 36.9%, 54.3%, and 51.7% G6PD activity in the spectrophotometric analysis).6 Because these subjects failed screening to enter the phase 2b clinical trial, a G6PD genotyping sample was not taken. Here, G6PD is linked to G6PD deficiency.