SPARC and cancer: Interestingly, the protein expression levels of two signature genes (THBS2, SPARC, MFAP2, MMP11 and THY1) were significant lower in normal tissues (Epithelial) than those in non‐metastatic and metastatic patients’ cancer tissues (Figure 4D), although there was no significant difference in protein expression levels between non‐metastatic and metastatic patients.