library_construction_protocol: NPCs were cultured and dissociated with 1:1 accutase:PBS (Invitrogen, #A1110501). CUT&RUN of POU3F2 in NPC samples was performed according to manufacturer instructions from Cell Signaling Technologies with minor modifications (Cell Signaling Technologies, #86652). Briefly, cells were collected (100k cells/reaction) and washed in buffer containing protease inhibitor cocktail and spermidine. Cells were bound to Concanavalin A Beads and incubated with primary antibody overnight at 4C at a 1:50 dilution (POU3F2: Cell Signaling Technologies, #12137S; H3K4me3: Cell Signaling Technologies, #9751). Input samples were prepared via treatment with proteinase K and RNase A, and chromatin was fragmented by sonication in a Bioruptor Plus (15 cycles of 30 seconds on/30 seconds off, high intensity setting). Input lysates were clarified and stored at -20C until library preparation. For the CUT&RUN samples, cells were permeabilized with digitonin and pAG-MNase enzyme was bound and activated by treatment with calcium chloride. DNA fragments were released from the cell and isolated via centrifugation. Input and CUT&RUN samples were purified using spin columns and assessed for concentration of DNA with a Qubit dsDNA high sensitivity assay (ThermoFisher, #Q33230). Library preparation was performed per manufacturer instructions (Cell Signaling Technologies, #56795) and sent for paired end (2x75bp) sequencing (Harvard Biopolymers Facility).