Total RNA was prepared from naïve or differentiated T cells using TriZol reagent (Invitrogen). cDNA was synthesized using Superscript reverse transcriptase and oligo(dT) primers (Invitrogen), and gene expression of beta–Actin (Actb), Grail, Il21, Il4, Gata321 (link),33 –34 (link), Il2 (F-GCGCACCCACTTCAAGCTCCA; R-CTGTGGCCTGCTTGGGCAAGT), Il5 (F-CGCTCACCGAGCTCTGTTG; R-CCAATGCATAGCTGGTGATTTTT), Il13 (F-GCTTATTGAGGAGCTGAGCAACA; R-GGCCAGGTCCACACTCCATA) and Stat6 (F-AGTCACTATAAGCCCGAACAG; R-GCCATTCCAAGATCATAAGGT) was examined with a Bio-Rad iCycler Optical System using iQ SYBR green real-time PCR kit (Bio-Rad Laboratories, Inc.). The data were normalized to Beta-Actin gene.