Abstract: This invention relates to modified T cells that inducibly express a bioactive molecule, such as IL-7, and constitutively expresses an antigen receptor, such as a T cell receptor or chimeric antigen receptor that binds to a tumour antigen. The modified T cells may comprise a nucleic acid construct that comprises a first nucleotide sequence encoding the bioactive molecule, a second nucleotide sequence encoding the antigen receptor; an inducible promoter operably linked to the first nucleotide sequence and a constitutive promoter operably linked to the second nucleotide. Nucleic acid constructs and vectors are provided, as well as T cells comprising such constructs and vectors and therapeutic methods and uses thereof.