A reporter construct was made consisting of an IRES domain, coding sequence for a variant of murine Thy1 (Thy1.1), and a loxP-flanked neomycin cassette. The vector was targeted to exon 3 of the gene locus immediately downstream of the stop codon and within the 3' untranslated portion of the gene. Chimeric founders were bred with B6.EIIa-Cre transgenic mice to remove the neomycin selection cassette. CD4+ T cells isolated from homozygote mice and cultured under Th17 conditions co-expressed both IL-17F and Thy1.1 in a log-linear manner. (J:143729)