CCR6 and infection: To determine whether ECs modulated expression of the identified HIV susceptibility markers on rCD4s, rCD4 cells were evaluated for expression of integrins VLA-4 (β1), LFA-1 (β2) and α4β7 (β7), and CCR6 on naive (CD45RA+) and memory (CD45RA−) subsets and markers of activation (CD69, Ki67) after being cultured alone or with TNFα-treated HUVECs in the absence of HIV for 4 days (equivalent to total coculture time in infection assays).