Briefly, the increased number of CD68+ TAMs and the increased number of indoleamine 2,3-dioxygenase (IDO) positive cells were associated with a favorable prognosis, whereas the increased number of CD204+ cells and a high ratio of CD204+/CD68+ cells, indicative of M2-like polarization, were associated with a poor prognosis in PCNSL (101). Here, CD68 is linked to primary central nervous system lymphoma.