PLAU and cancer: We have previously reported that HMW-HA (the main form of HA in the body) inhibits HABP2 activation while LMW-HA (generated in disease states, such as cancer, by hyaluronidase enzymes and ROS) activates HABP2 activity (11), and therefore, we examined the roles of HABP2 and HA on uPA activation in SK-LU-1 cells (Figure 2B).