(A) Scheme depicting the four experimental systems profiled in this study. Top left: Doxycycline-inducible OKMS (OCT4, KLF4, MYC and SOX2) fibroblast reprogramming to iPSCs. Bottom left: Human embryonic stem cells undergoing differentiation to neural progenitor cells. Top right: Bone marrow derived dendritic cells stimulated by lipopolysaccharide (LPS). Bottom right: Embryonic and adult mice brain. (B,C) Heatmaps of POI scores (visualized as in Fig. 1A) of all WTAP-dependent sites (rows) identified in one or more sample (columns), within genes expressed above the 60th percentile across all conditions (Methods) in human (B) or mouse (C). (D, E) Number of conditions (X axis, of a total of 7, as in B and C respectively, excluding any genetic perturbations) in human (D) and mouse (E), in which sites are identified as present (POI > 4). Sites were grouped into three equally sized groups, based on POI score.