
Superman's body is Kryptonian,
THEREFORE his sweat is Kryptonian.
The Big Bang Theory Season 2, Episode 11

Therefore, you may use my spot...
The Big Bang Theory Season 6, Episode 9

I would've expected the surprise
and THEREFORE not have been surprised.
The Big Bang Theory Season 10, Episode 6

Therefore, to not
play with it would be...?
The Big Bang Theory Season 5, Episode 20

Therefore, according to
the transitive property,
The Big Bang Theory Season 12, Episode 8