She ignored my suggestion—not that I care. [=I do not care that she ignored my suggestion]她对我的建议置之不理——我倒不在意。

Not that it matters much [=it does not matter much], but is the artist a man or a woman?虽然这并不很重要，但那个艺术家是男性还是女性？

Some people lie to get out of jury duty. Not that I ever would, of course. [=I would never lie to get out of jury duty]有些人为逃避陪审义务而撒谎。当然，我绝对不会。