We next tested whether PU. 1 gene expression can be affected by GATA-1 and therefore we upregulated GATA-1 by transfecting a GATA-1-expressing plasmid (pXMGATA-1) into AML-EL cells (OCI-M2, K562) and monitored the levels of PU.1 mRNA and protein for 72hrs. Here, GATA1 is linked to acute myeloid leukemia.