Out of the seven probes reported as significantly associated with PD in whole blood by Henderson-Smith et al., the two top probes showed associations at P < 0.05 with one cell type each (cg06889422 in CD4+ T cells, P = 0.042, and cg16133681 in CD14+ monocytes, P value = 0.042), both with direction of effect consistent with the whole-blood study (Supplementary Table 2). This evidence concerns the gene CD4 and Parkinson disease.