How many of these prominent mob parts weren't played by Italians? James Caan is not Italian, he's Jewish, right?

I know that Jamie-Lynn Sigler, who plays Meadow Soprano, is a mix of almost every ethnicity BUT Italian (and what a nice mix it is!).

How about Robert Iler, who plays AJ? What kind of surname is that? Doesn't sound Italian to me.

I also read that DeNiro is ethnically more Irish than Italian (true to his role in GoodFellas).

Any other examples?