Schematic representation of generation and targeting of induced pluripotent stem cells (iPSCs) derived from a patient with X-linked chronic granulomatous disease (X-CGD), as achieved by Zou et al²  Di-hydrorhodamine (DHR) test was used to confirm that patient-derived iPSCs differentiated into myeloid cells recapitulate the CGD phenotype. Insertion of the CYBB gene into the AAVS1 locus by zinc-finger nucleases (ZFNs) allowed rescue of the cellular phenotype. Professional illustration by Paulette Dennis.