For instance, two constructs consisting of two separate amyloid-forming hexapeptides—one derived from the microtubule-binding region of the human tau protein involved in formation of paired helical filaments of AD, the other from an amyloid-forming sequence from apolipoprotein A1—conjugated to polyarginine, exhibited selective cytotoxicity to cancer cells via formation of toxic oligomers by these cancer-targeting peptides (CTPs), relative to noncancerous cells [243]. Here, APOA1 is linked to Alzheimer disease.