We use the proximity effect to generate effective topological superconductors by placing metals with strong spin-orbit coupling in contact with a superconductor, aiming to produce Majorana zero modes useful for topologically protected quantum computation. In recent experiments, several quintuple layers of Bi2Se3 were epitaxially grown on the high-Tc material Bi2Sr2CaCu2O8+δ, and conflicting experimental results were reported. We use the standard mean-field approach to study this heterostructure and find it is unlikely to have a large proximity-induced superconducting gap. Despite the seemingly correct temperature dependence, the s-wave gap claimed to be observed may not be purely superconducting in origin. Future work on the proximity-induced bulk superconducting gap and the interfacial band structure should shed light on this issue. [ABSTRACT FROM AUTHOR]