PSEN1 and Alzheimer disease: Another—as I find-—very interesting aspect of this 2002 review is the fact that the cascade displayed in its summary figure begins with “missense mutations in APP, PS1, or PS2 genes.” However, in the legend, this is described as “the sequence of pathogenic events leading to AD proposed by the amyloid cascade hypothesis” with no further differentiation of the familial (genetic, early-onset) and non-familial (age-associated, late-onset) forms.