Tag:D4H(Y415A.A463W) can be used to monitor the subcellular distribution of cholesterol, if fused to an appropriate reporter protein, or to target a tagged protein to a particular subcellular localization via cholesterol binding. Tag:D4H(Y415A.A463W) is based on the cholesterol-binding D4 domain of perfringolysin O theta-toxin and was generated by mutagenesis of Tag:D4H, adding amino acid substitutions Y415A and A463W in addition to the the D434S change present in Tag:D4H (PMID:31548609).