A recent promising phase 1/2 clinical trial in the USA (NCT03056339) is being conducted to investigate the safety and efficacy of primary NK cells obtained from UCB carrying a CD19-CD28-CD3ζ-2A-iCasp9-IL15 construct in patients with relapsed/refractory B-cell ALL, CLL, and non-Hodgkin lymphoma. Here, IL15 is linked to non-Hodgkin lymphoma.