CCL2 and Parkinson disease: As shown in Figure 1, there was no significant difference between PD patients and controls regarding plasma levels of the evaluated chemokines CCL11/eotaxin (t = −0.967; P = 0.34, Student's t test), CCL24/eotaxin-2 (Z = −1,300; P = 0.19, Mann-Whitney test), CXCL10/IP-10 (Z = −0.035; P = 0.97, Mann-Whitney test), and CCL2/MCP-1 (Z = −0.148; P = 0.88, Mann-Whitney test).