Indeed, while genetic background is similar among CDD, AD, and DS mice, all derived from crossbreeding with the C57BL/6 mouse strain (i.e., C57BL/6 J for Cdkl5 KO mice; C57BL/6JEiJxC3Sn.BLiAFi for Ts65Dn mice, and C57BL/6 × 129/Sv for 3xTg-AD mice), the effects of P021 treatment in the mouse model of Alzheimer’s disease were evaluated exclusively in female mice, while a mixed female and male population of Ts65Dn mice were used as a model of Down syndrome. The gene discussed is CDKL5; the disease is early-onset autosomal dominant Alzheimer disease.