This is what they indeed found: first, within-twin pair differences in cortical amyloid were related to within-twin pair differences in cortical tau and secondly, within-twin pair differences in cortical tau were related to within-twin pair differences in episodic memory and finally, mediation model showed that the within-twin pair differences in tau mediated the association between within-twin pair differences in cortical amyloid and within-twin pair differences in episodic memory. Here, MAPT is linked to amyloidosis.