SRGN and esophageal squamous cell carcinoma: We also conducted a co-IP experiment using the cell lysates and CM of ESCC cells overexpressing FLAG-fusion SRGN (F-SRGN) and FLAG-fusion ∆GAG (F-∆GAG), and found that MDK was co-precipitated with SRGN in F-SRGN-overexpressing cells but not F-∆GAG-overexpressing cells (Figure 7D andFigure S9A).