Results showed that only the mRNA level of ACAN was significantly decreased in severe IDD compared to mild IDD group (Figure 2F–2K), while differences in XYLT-1, B4GALT7, C4ST-1, C6ST-1, and HYAL-1 between the mild and severe IDD group did not reach statistical significance. Here, HYAL1 is linked to intervertebral disk degenerative disorder.