Although ageing is considered a major risk factor for PD (Kesidou et al. 2023) due to age-related dysregulation of the immune system (immunosenescence) and as being responsible for the weakened response to novel antigens and increased susceptibility to infections, there is evidence for an attenuation in immunosenescence in PD, particularly for a reduction in senescent CD8 T lymphocytes, which may indicate a modification of the immunological response in the elderly (Kouli et al., 2022). Here, CD8A is linked to Parkinson disease.