These tables show the G1e and G4e nomenclatures respectively for the engineering variants of IgG1 and IgG4. This nomenclature describes the monoclonal antibodies having a Marketing Authorization (in the United States, in Europe or in Japan) and the variations in their amino acid sequence compared to the human IgG consensus according to the IMGT sequence (http: // www.imgt.org/IMGTScientificChart/Numbering/Hu_IGHGnber.html). The classification is made according to the date of obtaining the Marketing Authorization and based on the EU numbering of the amino acids of the immunoglobulin chains. In this nomenclature “dK” means that there is a deletion of the chain terminal lysine. G1e0 and G4e0 correspond to antibodies not showing a difference with the human amino acid chain. To avoid any confusion between engineering modifications and variations related to allotypes, we have clarified the latter. The following column shows the substitutions / deletions / additions / modifications that the protein has undergone: for example “F126L substitution” means that a phenylalanine at position 126 has been substituted by a leucine.