A liposomal formulation consisting of short-interfering RNAs (siRNAs) directed against ephrin type-A receptor 2 (EphA2) and encapsulated into 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine (DOPC) neutral liposomes, with potential antineoplastic activity. Upon internalization, EphA2-targeting DOPC-encapsulated siRNA can hybridize to EphA2 DNA and mRNA, thereby interfering with both the transcription and translation of EphA2, and thus inhibiting tumor cell growth. The cell-surface receptor EphA2, a member of the ephrin family of receptor tyrosine kinases (RTKs) involved in mammalian development, is overexpressed by a variety of different cancer cell types and plays an important role in tumor growth.