As a one-time galactic hitch-hiker, Franklin would exchange his medical services for free passage. He was one of few humans to have contact with the Minbari prior to the Earth-Minbari War, but his personal ethics prevented him from providing any information for Earth to use against them (And the Sky Full of Stars, In the Beginning). He follows the Foundationist religion, which takes into consideration all the religions of the various races and tries to find common elements (Walkabout, Meditations on the Abyss).
His father Richard, being an Earthforce General, tended to treat his family more like a military detail, which Stephen resented before finally coming to terms with him (GROPOS). He also managed to successfully find a cure for a long-running Markab plague - only too late (Confessions and Lamentations).
In order to cope with the increased pressures of work in MedLab, Franklin developed an addiction to stimulants (stims) (In the Shadow of Z'ha'dum, Confessions and Lamentations, A Day in the Strife, Ceremonies of Light and Dark) and, when he finally came to terms with the problem, resigned his commission and went walkabout to recuperate and "meet himself" to reason his problems out (Interludes and Examinations, Walkabout, Shadow Dancing).
Returning to his position, he was sent to Mars on a reconnaissance mission with Marcus where he had a fling with the resistance leader, Number One (Racing Mars, Lines of Communication), before returning again with the Shadow-influenced telepaths as part of Sheridan's plan to use them against Earthforce (The Face of the Enemy, Endgame). He also assisted in rescuing Sheridan from his imprisonment (Between the Darkness and the Light).
He was called upon by the Interstellar Alliance to advance research in cross-species medicine (Strange Relations), and then later by Earth to head their Xenobiological Research department after the departure of Dr Benjamin Kyle (The Ragged Edge, Objects at Rest), where he remains for at least another 20 years (Sleeping in Light).
He has spearheaded research on Earth regarding the Drakh virus (Each Night I Dream of Home).
Played by Richard Biggs, who had a regular role in the soap opera Days of Our Lives. According to his IMDB biog, he was completely deaf in one ear and partially deaf in the other. Sadly, Richard died of an aneurism on 22 May 2004.