Our data revealed a close positive correlation between the expression of P4HA2 and collagen biosynthesis-related genes (Col4A1, Col5A1 and Col6A1) in cervical cancer (Figure 6), which is also consistent with a previous report of a positive correlation between collagen biosynthesis and P4HA2 in breast cancer11. The gene discussed is COL6A1; the disease is cervical cancer.