Of special note, in July 2014 the US Food and Drug Administration (FDA) approved the first PI3K to be licensed, namely the PI3Kδ inhibitor idelalisib for different B-cell malignancies: as monotherapy for patients with relapsed follicular B-cell non-Hodgkin lymphoma and small lymphocytic lymphoma, and in combination with rituximab for those with relapsed chronic lymphocytic leukemia (CLL) [8, 9••, 10••]. This evidence concerns the gene PIK3CD and B-cell chronic lymphocytic leukemia.