The differential expression of VEGFR1 (FLT1) (t test adjusted p < 0.05) and multiple angiogenic-related signaling pathways may be representative of distinct mechanisms of endothelial cell recruitment and tumor vasculature formation between the two subtypes (Birdsey et al., 2015; Cao, 2013; Chrzanowska-Wodnicka, 2013; Hellström et al., 2007; Zhou et al., 2018; Zhu et al., 2017). Here, FLT1 is linked to neoplasm.