Because our results showed a positive relationship among VEGFR-2, Gab1 and MMP-9 in hilar cholangiocarcinoma, we proposed that the VEGFR-2/Gab1/PI3K/Akt signaling pathway was likely present in hilar cholangiocarcinoma and could influence MMP-9 expression. Here, MMP9 is linked to hilar cholangiocarcinoma.