Model of cell transformation by E26 and AEV avian leukemia viruses.

For explanation, see “Discussion.” Black arrows indicate infection by virus; black lines, differentiation potential; curved arrows, self-renewal; black bars, block of differentiation. The cell surface antigens expressed are indicated in red (erythroid markers) or blue (multipotent progenitor/thrombocytic markers). Highly expressed antigens are indicated by large letters; weakly expressed antigens by smaller letters.