There is tremendous potential for haematopoietic stem cell (HSC) and progenitor (CD34+) cell gene therapy for many diseases (reviewed in refs 1, 2), but as the field closes in on large global health burdens such as HIV and haemoglobinopathies, lack of a portable technology for standardized manufacture of gene-modified CD34+ blood cell products becomes a critical barrier to widespread clinical use. The gene discussed is CD34; the disease is hemoglobinopathy.