Total RNA (1 μg) was prepared from HUVECs and BRECs, and first-strand cDNAs were synthesized with an oligo dT-primed Moloney murine leukemia virus (MMLV) reverse transcriptase (Invitrogen-Gibco). A primer pair for a constitutively expressed gene, glyceraldehyde 3′-phosphate dehydrogenase (GAPDH), was included in each assay as an internal control. Nuclease-free water was included as a negative control. The primer sequences used (Integrated DNA Technologies, Inc., Coralville, IA) for HUVECs were as follows: FKN sense, 5′-ATGCTGCCCTGTGAGTACTAC-3′, and antisense, 5′-GGTCCAAAGACAAGTTAGTCC-3′, 534-bp amplicon; CX3CR1 sense, 5′ATGCTTGGCTTCTCATACGTC-3′, and antisense, 5′-CATTATTACAATTGTTTTCGAGC-3′, 710-bp amplicon. The primer sequences used for BRECs were as follows: FKN sense, 5′-ATTCTGTGCTGACCCAAAGG-3′, and antisense, 5′-AGCCTCGTTGAAAAGCTCAA-3′, 439-bp amplicon; CX3CR1 sense, 5′-CCATGAACAACCGGACCG-3′, and antisense, 5′-ATGGCTAAATGCAACCGT-3′, 445-bp amplicon. The GAPDH sense, 5′-CCACCCATGGCAATTCCATGGCA-3′, and antisense, 5′-TCTAGACGGCAGGTCAGGTCCACC-3′, 597-bp amplicon, were used for the primer sequence of the internal control. The polymerase chain reaction cycling conditions were 95°C for 5 minutes followed by 30 cycles of 95°C for 1 minute, 55°C for 2 minutes, and 72°C for 3 minutes, ending with a 10-minute extension at 72°C. Amplification products were characterized by size fractionation on 1% agarose gels.