unlike other acute leukemia viruses , which can transform various undifferentiated cells , have large unique sequence cellular gene inserts fused to helper virus gag genes , and have one known genome-length intracellular mrna , the spleen focus-forming virus transforms only specific hematopoietic stem cells , is an env gene rather than a gag gene recombinant virus , and has a second distinct and smaller class of intracellular mrna .
C0007634
cellular
C0018956
hematopoietic stem cells