New cancer immunotherapy uses engineered T cells to target a common genetic alteration Researchers developed a prototype for a new cancer immunotherapy that uses engineered T cells to target a genetic alteration common among all cancers. The approach, which stimulates an immune response against cells that are missing one gene copy, called loss of heterozygosity (LOH), was developed by researchers at the Ludwig Center, Lustgarten Laboratory and the Bloomberg~Kimmel Institute for Cancer Immunotherapy at the Johns Hopkins Kimmel Cancer Center. Genes have two alleles, or copies, with one copy inherited from each parent. Cancer-related genetic alterations commonly involve the loss of one of these gene copies.