RT-qPCR demonstrates significant increases in relative gene expression of various tight junction components (A. CLDN3, B. CLDN15, C. OCLN, D. TJP1/ZO-1) in transplanted HIOs (tHIOs) after four (n=6) or eight (n-4–5) weeks in vivo compared to HIOs after 28 days in vitro (n=7–8). There was no significant difference in relative gene expression of tight junction genes between tHIOs at four and eight weeks in vivo. Values are expressed as the mean ± SEM. *p<0.05, ***p<0.001, ns denotes not significant (p≥0.05).