CD28 and neoplasm: Polyclonal activation of T cells is commonly used in the generation of gene-modified T cells encoding either tumour-specific chimeric antigen receptors or T-cell receptors.6, 13, 14, 16 To demonstrate the capacity of SR to support the ex vivo expansion of gene-modified T cells, polyclonal T cells activated with CTS Dynabeads CD3/CD28 were transduced with a GFP-expressing lentiviral vector (16–20 h after activation) and the expression of GFP was analysed by flow cytometry on day 7.