Duration of neutropenia trended to lower values among patients receiving CYP3A4–inhibitors than among patients who did not (median 34.5 days vs 20.5, respectively; p 0.19), as well as duration of thrombocytopenia (median 17 days vs 21.5 days, respectively; p 0.923). This evidence concerns the gene CYP3A4 and Decreased total neutrophil count.