MMP9 and Hydrocephalus: Therefore, we measured the levels of NLRP3, MMP‐9 and IFN‐γ in the serum of patients with craniocerebral trauma 1 day after craniotomy by ELISA kits, and found that the levels of NLRP3 inflammasome, MMP‐9, and IFN‐γ in the serum of patients with intracranial infection and hydrocephalus were significantly higher than those in the control group (all P < 0.01) (Figure 1a–c).