SHP2 mediated the CXCL12α/CXCR4 signal responsible for guiding cerebellar granule cell migration.64 Aggregations of proteins, including prions, amyloid β, tau, and α-synuclein, as well as hypoxia and oxidative stress, lead to low-grade chronic inflammation in neuroglial cells.65,66 Liu et al. found a beneficial effect of SHP2 in alleviating PD in mice. Here, PTPN11 is linked to Parkinson disease.