Though increased levels of CHI3L1 have been associated with disability accrual in PPMS (Pérez-Miralles et al. 2020), CHI3L1, IL12p40 and VEGF have also been associated with acute inflammatory disease activity (Lu et al. 2021; Masvekar et al. 2021; Proescholdt et al. 2002; Su et al. 2006). The gene discussed is CHI3L1; the disease is primary progressive multiple sclerosis.