Possible pathways for aberrant lineage modification.63 A block in one lineage could result in lineage diversion to another lineage before commitment. Alternatively, committed progenitors could either undergo dedifferentiation followed by redifferentiation (gray arrows) or directly trans-differentiate through a biphenotypic intermediate. Alterations within a committed progenitor could also result in the loss of lineage-specific markers without dedifferentiation, as described in Hodgkin lymphoma.