Abstract: The present invention relates to a vector encoding a wildtype or truncated form of erythropoietin receptor (EpoR) to promote T cell survival and proliferation. Specifically, it exemplifies a bicistronic vector that expresses a truncated EpoR with an anti-CD19-41 BB-003? chimeric antigen receptor (CAR) that has a greater ex vivo expansion than CAR-T cells and demonstrates a significantly higher anti-leukemic activity in vivo. It also describes the method of producing cells expressing said vector and the use of these cells to kill CD19+ tumour cells.