We tested the activity of our safety switch by introducing the gene into donor t cells given to enhance immune reconstitution in recipients of haploidentical stem-cell transplants.

Methods: In this pilot study, 58 patients, 33 with high-risk or advanced leukemia, were transplanted with cells from an HLA-haploidentical family donor with at least 1 of 6 loci mismatched.

Besides technological advances, choosing the most appropriate donor is also an important factor to overcome the HLA barriers in haploidentical HSCT.