TGFB1 and leukemia: In accordance with the transcriptional repression functions of TGIF1, mRNA expression profiling identified a number of genes which were up‐regulated in Tgif1‐null leukaemic cells, with almost half the genes differentially expressed between knockout and wild‐type leukaemia cells involved directly or indirectly in TGF‐β signalling (Figure 5).