Differential gene expression along lineages supports mathematical model predictions. (A) Expression of Cebpa and Ikzf1 along the HSC lineage, transcription factors important for myeloid and lymphoid development, respectively. (B) Expression of Myc and cell-cycle gene, Ccnb2, along the MyP lineage, associated with cell proliferation. Lines in A and B are NB-GAM fits, shaded regions are 95% confidence intervals, and transparent points are individual cell data. Italicized numbers are P values and degrees of freedom used for NB-GAM fits specified by k.