RMF were plated in 0.4μm pore Transwell dishes (Costar) and co-cultured with vHMEC expressing either control luciferase short hairpin (sh-Luciferase), activin A short hairpin (sh-activin A), vector control, TRF2 or hTERT (19 (link), 20 (link)). RNA was isolated from RMF 48 hours after initiation of co-culture.