Using an established, highly efficient, and reproducible protocol (32), we generated microglial cells from these iPSCs. We first derived primitive macrophage progenitors (PMPs) from iPSCs (Fig. 1, A and B, and table S1). Across multiple iPSC lines, more than 90% of the PMPs exhibited expression of the hematopoietic progenitor cell markers CD235 (Fig. 1, C and D) and CD43 (Fig. 1, E and F). After confirming the PMP cell identities, we differentiated these PMPs into microglial cells by adding interleukin-34 (IL-34) and granulocyte-macrophage colony-stimulating factor (GM-CSF) for 1 week. Microglial identity was confirmed through immunostaining for a panel of microglia-specific markers, including IBA1, P2Y12, CX3CR1, TMEM119, and PU.1 (Fig. 1G).
