In order to better understand the mechanisms underlying MSC immune-regulatory ability on T cells, pro- and anti-inflammatory cytokines (i. e. IFN-γ, TGF-β, IL-2, IL-6, IL-10) were measured in MSC:PBMC co-cultures (1:2 ratio) stimulated with PHA for 3 HD-MSC samples, 3 WAS-MSC samples, 2 CGD- and 2 SCID-MSCs (RAG-1 deficiency) samples. The gene discussed is IL2; the disease is hyperinsulinemic hypoglycemia, familial, 4.