NPTX2 and Alzheimer disease: There was also a weak but significant association between CSF NPTX2 levels and cortical thickness in the whole cohort (β (SE) = 0.08 (0.02), p < 0.0001, Figure 4J), the AD group alone (β (SE) = 0.06 (0.03), p < 0.05, Figure 4L) and in the CU group alone (β (SE) = 0.04 (0.02), p < 0.05, Figure 4K).