For example, oscillations in serum ferritin (a marker of a chronic inflammatory state) are associated with antiviral therapy in chronic hepatitis C (Kronborg et al., 2021); oscillations in interleukin IL-2 (a pro-inflammatory mediator) are reported in adaptive strategies for IL-2 therapies (which are of relevance to hepatitis treatment) (Ju & Tacke, 2016); and (although not explicitly modelled here), oscillatory dynamics in T cell functions have been associated with hepatitis B virus (Hilscher & Shah, 2020). Here, IL2 is linked to chronic hepatitis C virus infection.