['Partial DiGeorge syndrome (pDGS) is caused by deletion of the 22q11.2 region. Within this region lies CrK-like (CRKL), a gene encoding an adapter protein belonging to the Crk family that is involved in the signaling cascade of IL-2, stromal cell-derived factor 1α, and type I interferon. Although recurrent infections can be observed in patients with deletion of chromosome 22 syndrome, the immune pathogenesis of this condition is yet not fully understood.', 'We aimed to investigate the role of CRKL in T-cell functional responses in patients affected with pDGS.', 'Protein expression levels and phosphorylation of CRKL were evaluated in patients with pDGS. T-cell functional assays in\xa0vitro and gene-silencing experiments were also performed.', 'CRKL protein expression, as well as its phosphorylation, were reduced in all patients with pDGS, especially on IL-2 stimulation. Moreover, T\xa0cells presented impaired proliferation and reduced IL-2 production on anti-CD3/CD28 stimulation and decreased c-Fos expression. Finally, CRKL silencing in Jurkat T\xa0cells resulted in impaired T-cell proliferation and reduced c-Fos expression.'] Is reduction of CRKL expression in patients with partial DiGeorge syndrome associated with impairment of T-cell functions?