CAL-101 (idelalisib or GS-1101) is a potent inhibitor of the delta isoform of the 110 kDa catalytic subunit of class I phosphoinositide-3 kinase (PI3K) with IC50 of 2.5 nM in cell-free assays. CAL-101 decreases pAktS473, pAktT308, and the downstream targ