IL-15 synergizes with iMC to enhance NK persistence in vivo. (A) NSG mice were engrafted with 1 × 10⁷ NK cells transduced with iRC9-ΔCD19 iRC9-ΔCD19-iMC or iRC9-IL15-ΔCD19-iMC and eGFPFfluc retroviral vectors. Mice subsequently received weekly IP vehicle only (Veh) or rimiducid (Rim) injections of 1 mg/kg in the vehicle. (B) Gene-modified NK cells levels were assessed by BLI weekly; 2-way analysis of variance (ANOVA) was used to compare differences among groups (P < .01). (C) Mice weights were assessed weekly; 2-way ANOVA was used to compare differences among groups (P = .30). p, photon; sr, steradian.