ICAM1 and common variable immunodeficiency: Several of these differentially expressed genes in both the CVID cohort and the CVID twin, include relevant genes for B-cell immune response such as CCL22, CD70, ICAM1, LGALS9, CD72 or PTPRC. Inspection of the CVID Ib subcohort led us to identify additional dysregulated genes shared with the CVID twin.