In order to provide a solid practical and theoretical basis for the subsequent research of targeted inhibitors, the expression levels of MMP9 in different cancers from GEPIA2 database were observed and analyzed to gain a comprehensive understanding in expression pattern, including SARC (sarcoma), GBM (glioblastoma multiforme), KIRC (kidney renal clear cell carcinoma), LUSC (lung squamous cell carcinoma), COAD (colon adenocarcinoma) and BLCA (bladder urothelial carcinoma). Here, MMP9 is linked to squamous cell lung carcinoma.