Since we have found that Ang II-mediated cardiac hypertrophy depends on the expression of PLZF, and that PLZF activation is driven by AT2 in the heart [15]; and since GATA4 is one of the well known factors involved in cardiac development and hypertrophy [26], we examined the possible transcriptional role of PLZF on GATA4 gene expression by luciferase assay in R3T3 cells which express the AT2 receptor but not AT1. This evidence concerns the gene AGTR1 and cardiac hypertrophy.