Targeted deletion of the adenosine A2aR or A3R does not correct the effects of ADA deficiency in FTOC. FTOCs were performed at day 15 of gestation with fetal thymuses from A2aR–/– and A3R–/–Adam1/m1 mice and appropriate controls. A2aR+/+ (a and b) and A2aR–/– (c and d) fetal thymic lobes were cultured for 8 days in the presence (b and d) or absence (a and c) of 5 μM dCF. A3R–/–Ada+ (e) and A3R–/–Adam1/m1 (f) fetal thymic lobes were cultured for 5 days. At the end of culture, thymocytes were harvested, counted, and stained with FITC-anti-CD4, PE-anti-CD8, and PI to exclude dead cells. The data are representative of one experiment out of two.