The structure of the complex between the transcription cofactor Vgll1 and the 
transcription factor TEAD4, the mammalian equivalent of the Drosophila Vestigial 
and Scalloped, respectively, is determined in this study. Remarkably, Vgll1 
interacts with TEAD in a manner similar to the transcription coactivators, as 
well as oncogenes YAP and TAZ, despite having a varied primary sequence. 
Vgll1-TEAD complex upregulates the expression of IGFBP-5, a 
proliferation-promoting gene, and facilitates anchorage-independent cell 
proliferation. The YAP/TAZ-TEAD complex also upregulates several other 
proliferation-promoting genes and also promotes anchorage-independent cell 
proliferation. Given its structural and functional similarity to YAP/TAZ, Vgll1 
has the potential to promote cancer progression.