In contrast, in all pyramidal layers of the HC of PD patients, TLR2 IR was low and comparable to the level of control subjects, and TLR2 IR only in the CA2 was slightly but significantly higher relative to the other CA regions (Figure 11c; CA2 vs CA1/CA4/CA3 p < 0.02; CA2 Mean = 0.8 ± 0.2; CA1 Mean = 0.5 ± 0.2; CA4 Mean = 0.5 ± 0.2; CA3 Mean = 0.7 ± 0.2). Here, TLR2 is linked to Parkinson disease.