To summarize, together with our previous study31, we demonstrates a pivotal role of PLGF in the metastasis of LC, in which LC cells not only produce PLGF to activate MMP3 through an autologous way via ERK/MAPK signaling pathway31, but also secretes PLGF to polarize macrophages into TAM in a TGFβ-receptor-signaling-dependent manner, which subsequently activates MMP9 in TAM. This evidence concerns the gene MMP9 and laryngotracheoesophageal cleft.