FLT4 and Chylothorax: Transgenic mice that express a soluble version of VEGFR3 have been used to study the pathophysiology of lymphedema (Mäkinen et al., 2001; Rutkowski et al., 2010), whereas VEGF-C transgenic mice have been used to model pulmonary lymphangiectasia (Yao et al., 2014), to study the pathophysiology of chylothorax (Nitschké et al., 2017), and to identify the specific function lymphatics serve in inflammation (Huggenberger et al., 2011) and cancer (Mandriota et al., 2001; Hirakawa et al., 2007).