seeing as the good Dr is made into management in the 4th season,
and given the immense time-frame it takes for anyone to first go through premed, then med-school, then internship/ residency, followed by specialisation and practising for a number of years,
ALL before then going on to become such a noteworthy scientist...
also...given his relationship with the girl (named?-who looked in her late 20;s/early 30's) in the end of S4
I predict that Klein would be at least in his late 40's if not early 50's...
