What of it?
What does the above sentence mean?
That you do not feel a statement or comment just made to you has validity or anything worth your consideration.
A: The Principal has banned cycling on campus.
B: What of it? I don't cycle.
Even more dismissive is "So what?"
...even 'So..?'; also 'And...?' or 'And then?' (I think this may have something to do with the French 'Et alors?')
"I care about this... why?"