because ...; for ...; the reason being ...
as for ...; when it comes to ...; regarding ...; how about ...
行けないというのは忙しいからだ。
The reason I cannot go is because I am busy.
彼が怒ったというのは本当ですか。
Is it true that he got angry?
というのは冗談だったようです。
It seems that was a joke.