A modified BAC construct was generated that consisted of an insertion immediately upstream of the stop codon in exon 3 of the Ccl2 gene of nucleotides encoding the HA peptide (-YPYDVPDYA-), followed by a 19 residue aphthovirus 2A cleavage site (-APVKQTLNFDLLKLAGDVESNPGP-), a furin cleavage site (-RAKR-), and aa 2239 of enhanced GFP. The EGFP coding sequence was followed by a stop codon. (J:171379)