VEGFA and Patent ductus arteriosus: Overall, it has been shown that the rough tumor microenvironment of PDA cancer cells renders them chemoresistant, and in combination with HuR’s posttranscriptional regulation of specific target genes (COX-2, VEGF, c-Myc, WEE1 and PIM1) [32,41,75,76,77], cell growth and survival are enhanced.