IL6 and Parkinson disease: 2021). Another observational research from China found that neither any significant difference in peripheral IL‐6 levels between PD patients and controls nor was there a statistical association between IL‐6 concentrations and QSM values in PD patients (Xu et al. 2022). Similarly, an observational study from a European population reported no association between IL‐6 and brain iron content in a cognitively healthy population (Spence et al. 2024).