Former WWE champion CM Punk came out with an attack on WWE’s partner Susan G. Komen, calling the largest and most-funded breast cancer organization a scam.

“If you’re going to give money to a company that claims to raise money for finding a cure for cancer, please do some research. Komen is a scam,” Punk wrote on his Twitter.

Komen has over 100,000 volunteers across the world and partners with some of the largest brands including Bank of America, American Airlines, HP, Ford, and WWE among others.

After receiving a ton of criticism for his tweet, the UFC fighter responded with, “The truth is never popular. F*ck all you crazy asses. Read a book.”

WWE partners with Susan G. Komen every October and donates money from merchandise sales and raises breast cancer awareness through WWE television and online properties.