In an attempt to further dissect the immunoregulatory mechanism of PTX in chronic experimental CD, we analyzed the frequencies of naïve, memory and activated T-cells studying the expression of CD44, a chondroitin sulfate proteoglycan receptor associated with cell migration to peripheral tissues, and CD62L, a marker of T-cell homing to lymph nodes [31]. The gene discussed is SELL; the disease is Cowden disease.