PLG and Alzheimer disease: Then, we performed subgroup analyses between APOE-ε4 carriers and noncarriers among those in the AD group and found that plasma angiostatin levels had a positive correlation with CSF t-tau levels (R2 = 0.4049, p = 0.0144) but did not correlate with CSF p-tau (p = 0.6170) (Fig. 3C, D).