In non-neoplastic mucosa distant from gastric cancer (Figure 3 and Figure 4; Table 2 and Table 3), CVID cases harboured higher Foxp3+, GATA3+ and PD-L1+ intraepithelial lymphocytes (p < 0.001; p = 0.014; p = 0.011). Here, FOXP3 is linked to common variable immunodeficiency.