After incubating with both GSNO (200 μM) and purified Hb (3 μM), a significant decrease in a nonclassical monocyte count was observed in vitro (Figures 3(c) and 3(d)) indicating a possible role of circulating free Hb and NO in monocytopenia in hemolytic patients. The gene discussed is GSTM1; the disease is Decreased total monocyte count.