One particular point, a later addition to the manuscript, has been much discussed. This states that Leonardo painted a portrait from life of "Piero Francesco del Giocondo" (or possibly just "Francesco del Giocondo"), respectively the son and the husband of Lisa del Giocondo, usually considered the sitter for the Mona Lisa.[8] Frank Zöllner argues that the author of the note simply made a mistake, and was referring to the Mona Lisa.[9]