Similarly, decreased expression of CLDN4 was found in the colon in aviremic individuals with a variable degree of immune recovery on cART [25], posing the question as to whether differences in TJ complex protein expression exist according to the extent of CD4+ T-cell gain, given literature reports of higher T-cell activation and microbial translocation in treated subjects with persistent CD4+ T-cell deficiency [4, 6, 18–20]. This evidence concerns the gene CD4 and congenital T-cell immunodeficiency.