Surprisingly, even though two groups observed enhanced IFNγ production by Tfh in CVID patients (77, 78), Le Coz et al. did not, rather finding increased IL-21+ cells and accordingly efficient helper B cell function in CVID Tfh despite observing a Tfh 1/Tfh 2-17 imbalance (80). Here, IL21 is linked to common variable immunodeficiency.