SNAI1 and pulmonary arterial hypertension: SNAIL is a master regulator of endothelial-to-mesenchymal transition involved in tumor metastasis, kidney fibrosis, and pulmonary hypertension.58–60 Although the function of SNAIL in vascular SMCs is not known, it was recently found that closely related transcription factor SLUG was involved in SMC phenotypic regulation during atherosclerosis.61 The absence of interaction with MECP2 could be due to technical limitations of the chromatin immunoprecipitation approach, in particular, the limited availability of chromatin immunoprecipitation grade antibodies.