https://www.sirtuininhibitor.com/2016/02/18/the-gtm-label-refers-to-the-tf-module-made-up-of-gata4-tbx5-and-mef2c-d-puromycin-was-utilised-to-positively-select-for-cells-activating-the-transgenic-cardiac-promoter-element-in-isolated-mefs-ad/