DC lineage potential is clearly present in ETPs and DN2a cells (63–65), and when we specifically checked the DN2a and DN2b populations, we found that ikaros and pu.1 expression became elevated in the DN2a stage, which may serve as a preparatory phase for initiation of arrest in T cell-lineage commitment and switching to DC, which drives DN2b to DC commitment in tumor host. The gene discussed is SPI1; the disease is neoplasm.