The most frequent grade 3/4 AEs were neutropenia (24.8%), diarrhea (14.7%), anemia (14.7%), and thrombocytopenia (11.6%) and similar rates of grade 3 neutropenia (27%) were observed in a Phase I trial of the PI3K-δ selective idelalisib, also in patients with relapsed non-Hodgkin lymphoma (29). The gene discussed is PIK3CB; the disease is anemia.