AKT1 and common variable immunodeficiency: After anti-IgM stimulation, the mean fluorescence intensity (MFI) of phosphorylated AKT and mTOR was overall comparable in B-cell subsets of CVID patients and HD (Figure 1B,C); however, phosphorylation of S6 was significantly reduced in patients’ CD21low and CD21pos B cells (Figure 1D).