CCR9 and atopic conjunctivitis: To establish the potential involvement of the specific antigenic-stimulation in the expression of FOXP3 and in the upregulation of cell migration receptors in PBMC from patients with PAC, we assessed the percentage of CD4, CD25, FOXP3, CCR4, CCR7, CCR9, CD103, and CD108 after Der p stimulation in 7 patients with active perennial allergic conjunctivitis.