,10,11,12 Sufficient numbers of MART1-specific CTLs were prepared using HLA-A∗02:01, CD80-, and CD83-producing aAPCs and infused into patients with melanoma; the adoptively transferred T cells persisted in vivo, preferentially localized to tumor sites, and mediated an antigen-specific immune response characterized by clinically meaningful tumor destruction.13 The gene discussed is CD80; the disease is neoplasm.