Jacqueline London (Emeritus Professor at University Paris-Diderot) has completed her PhD in the Pasteur Institute under the direction of Pr. Jacques Monod and Professor M. Goldberg in the field of protein folding and bacteriology. She moved to immunology in Necker’s hospital under the direction of Pr JF Bach and then was a visiting scientist at NIH . After coming back to Paris she settled a laboratory in molecular biology at the Blood Center and cloned glycophorins A and B (13 papers). She then moved again to Necker’s Hospital where she joined the group working on Down syndrome (Trisomy 21) and published some 35 papers on different aspects of trisomy 21 using transgenic mice for some chromosome 21 genes: APP, CBS, DYRK1A and SOD1. Since many years she tried to push the correlation between Alzheimer disease (AD) and Down syndrome (DS) and recently worked on neurotransmitters in some transgenic mice APP, and DYRK1A in the laboratory settled in the University Paris Diderot called now Paris-Cité University. She was teaching Parkinson disease and Alzheimer disease and protein aggregates since many years. She also settled in 1990 AFRT (French Association for Research on Trisomy 21) and is now AFRT Vice-president. AFRT initiated in 2005 the International Day for Trisomy 21 which is now recognized as World Down Syndrome Day (WDSD and JMT21 in french).