(A) The transgene consists of an inducible caspase 9 (iC9), and a selectable marker, truncated CD19 (ΔCD19), linked by a 2A-like sequence, which encodes a cleavable peptide. iC9 consists of a drug-binding domain (FKBP12-F36V) connected via a short linker (SGGGS) to human caspase 9. (B) Conditional Caspase 9 dimerization is induced in the presence of CID (AP1903), cleaving caspase 3 and leading to cell apoptosis.