CD33 and early-onset autosomal dominant Alzheimer disease: Although the association of CD33 with Alzheimer’s diseases has not been thoroughly elucidated, literature data supports the hypothesis that through the modulation of immune cell functions (such as phagocytosis, cytokine release, apoptosis, etc.), CD33 could be implicated in the suppression of amyloid fragment uptake [12,18,23,25,26,27].