SP1 and acute myeloid leukemia: In HEK 293, HeLa, AML, HL‐60, and HEL cells Sp1 positively contributes to SET‐α gene transcription in vivo while Sp1 knockdown leads to reduction in SET‐α mRNA level, whereas Sp1 deficiency has no effect on SET‐β transcription.63 Furthermore, reporter assays confirmed that Sp1 overexpression failed to impact on SET‐β promoter activity indicating the distinct transcriptional regulation between the 2 isoform transcripts.