Figure 9. Model of the functions of lamprey HMGB1.

Lamprey HMGB1 has various roles, such as binding DNA, which may maintain DNA structure, and inducing cell proliferation, which may promote the evolutional stability of the parasitic lamprey. After LPS/ConA stimulation, the Lj-HMGB1 gene was up-regulated in gills, which in turn promoted the release of proinflammatory mediators, such as TNF-α, to alert the lampreys to underlying danger and prevent the invasion of bacteria or viruses or other exogenous injuries.