HAS2 and neoplasm: Besides, HYAL fragmented HA some ROS-fragmented HA also found to be involved in overproduction of HA in tumours growth, invasion and spreading.66 The over-expression of synthase HAS2 and HAS3 results in enhancing HA overproduction, which triggers the production sarcomas and other melanoma cells.67,68 HA trigger the formation of new blood vessels and also circulation of tumour cells via growth and invasion seen in some studies.