POU1F1 and neoplasm: Tumor cells were organized into a common precursor population (Lineage_undiff_1 to Lineage_undiff_3) and three lineage-specific branches: the PIT1-lineage was subdivided into four subpopulations (Lineage_PIT1_1 to Lineage_PIT1_4), the TPIT lineage into two subpopulations (Lineage_TPIT_1 and Lineage_TPIT_2), and the SF1 lineage into three subpopulations (Lineage_SF1_1 to Lineage_SF1_3) (Fig. 4a, b).