P4HA3 and cancer: We also analyzed the associations between P4HA3 expression and MMPs (Matrix Metalloproteinase) which also are crucial in cancer metastasis, and found that P4HA3 was significantly positively correlated with the expression of MMPs including Matrix Metalloproteinase 9 (MMP9), Matrix Metalloproteinase 7 (MMP7), Matrix Metalloproteinase 2 (MMP2) and Matrix Metalloproteinase 14 (MMP14), especially MMP2 and MMP14 (Fig 3C).