IL17RA and Parkinson disease: Based on the upregulation of CCL2, interleukin-17 receptor (IL17-R), and major histocompatibility complex (MHC) genes human leukocyte antigen B (HLA-B) and C (HLA-C) in senescent midbrain DA neurons (Riessland, 2020), it is plausible that the SASP of senescent midbrain DA neurons in PD patients triggers both an adaptive and innate immune response.