SP1 and T-cell leukemia: This was similar to Kuhlmann’s reported that in adult T-cell leukemia (ATL) patients, the human T-cell leukemia virus type 1 protein HTLV-1bZIP factor (HBZ) leaded to target gene activation by forming a heterodimer with Jund and interacting with SP1 in the hTERT promoter region (Kuhlmann et al., 2007).