PDCD1 and cancer: To fully clarify the immune value of CD68 in pan-cancer, we next studied the correlation between CD68 expression and large numbers of immune checkpoints in pan-cancer and found that high levels of CD68 were significantly and positively correlated with some key checkpoints, including LAIR1, HAVCR2, LGALS9, and PD-1 in most of the 33 tumor types.