Figure 1. Model of Gfi1 function in T-ALL: p53 dependent transcription of target genes is activated in the absence of Gfi1.

DNA damage occurs in tumor cells in the process of malignant transformation according to the concept that oncogenic lesions induce a DNA damage response. As a consequence p53 is activated, but is controlled by Gfi1 because it can recruit LSD1 to p53 to keep it de-methylated at its C-terminus. If Gfi1 is lacking, LSD1 cannot de-methylate p53 with the consequence that p53 is activated and causes the over-expression of apoptosis inducing genes, which eventually leads to the elimination of leukemic cells.