In the original Deus Ex, the protagonist is named "JC Denton". In its sequel, set twenty years later, the protagonist is named "Alex D". In the latest two games (Human Revolution & Mankind Divided), set thirty years before the original, the name of the protagonist is "Adam Jensen". All three protagonists bear a physical resemblance, being Caucasian men with similar builds, hair colors and appearances.
The Deus Ex franchise is tied together by various characters that appear throughout its timeline, but is there any evidence of a familial relationship between the three protagonists listed above?