Can we be sure that we don't need the appendix ?

We used to think tonsils are optional as well, and there seem to have been some studies that find a link between tonsillectomy & Crohn's, Hodgkin's or even breast cancer (from wikipedia).

There surely must be vestigial parts in our organisms, like the one in the article, but more often than not we have no fucking clue how they interconnect with the whole and what their function is.

I think. I'm not a doctor or anything.