In fact, this behavior was observed for a number of factors known to promote PDA progression and/or therapeutic resistance (e.g., collagens, proteoglycans, hyaluronan synthesis, lysyl oxidase, IGF-1, IL-6, CSF1, etc.; Supplemental Figure 4), while others, such as CXCL12, appeared more phenotype specific. This evidence concerns the gene CXCL12 and Patent ductus arteriosus.