It seems we all might have an apology to make, as new research has confirmed that the appendix isn't the useless waste of space that we all believed it to be.
In fact, far from being redundant, it may well have actually been silently helping keep our immune system in check all these years.
Can we get a refund on that appendectomy?
The functionality of the appendix has long baffled scientists - Charles Darwin believed it was a throwback to our evolutionary past and was used for digesting leaves, a theory that later came to emerge as the leading hypothesis.
However, a study released this week suggests the appendix may be completely unrelated to digestion and is actually be an important secondary immune organ, a reservoir for good gut bacteria that bolsters our defences.
Back in 2007, a group of scientists were the first to suggest the appendix may act as the 'safehouse' for bacteria, and now Dr. Heather Smith from Midwestern University Arizona College has found more evidence to support the claim.
Smith and her team studied 533 mammalian species in the animal kingdom, looking for the presence of the appendix.
They found that in those species where the organ had evolved, it almost never disappeared again; a strong case to suggest that it does serve a purpose.
When they looked closer they found that those animals with an appendix have higher average concentrations of innate lymphoid cells in their tissue that protect the body from infections.
But don't worry if you've already had yours removed, Smith told Time magazine it just means you might take a little longer to get better when you fall ill.
"It might take them slightly longer to recover from illness, especially in those in which the beneficial gut bacteria has been flushed out of the body," said Smith.