LMO2 and leukemia: First, as seen, for example, by the insertional activation of oncogenes in gene therapy, approaches to cure the X-linked severe combined immunodeficiency disease (X-SCID), the strong promoter of the long terminal repeats (LTRs) of the retroviral constructs, activates neighboring promoters (in the case of X-SCID the oncogene LMO2 promoter, resulting in leukemia [55]).