HYAL4 and central nervous system cancer: In the present study, our results confirmed that among the six hyaluronidases (HYAL1, HYAL2, HYAL3, HYAL4, HYALP1, SPAM1), only HYAL2 was overexpressed in glioma patients, and HYAL2 overexpression was negatively correlated with the survival time of glioma patients.