Synder et al. demonstrated that STAT3 binds constitutively to the Nkx-2.5 promoter and inducibly to Tbx5, as well as GATA4 promoters in response to LIF treatment, enhancing the expression of these cardiac transcription factors in P19CL6 embryonic carcinoma (EC) cells [45]. This evidence concerns the gene GATA4 and embryonal carcinoma.