TFRC and ovarian cancer: Hybrid-or reverse hybrid-SELEX have been used to isolate aptamers targeting the RETC634Y mutant receptor tyrosine kinase overexpressed in PC12 cells [108], the HER-2 tyrosine kinase receptor expressed in SKOV3 ovarian cancer cells [109], CD16α on Jurkat cells overexpressing CD16 alloforms [64], integrin α6β4 on PC-3 cells [110], the transferrin receptor CD71 expressed in HeLa cells [94].