Nike stuck by Tiger Woods in the wake of his infidelity and gave Michael Vick an endorsement deal after Vick had served time in prison for his role in a dogfighting ring, which included killing dogs that underperformed.

But this week, the company emphasized that there is one transgression it cannot tolerate: cheating.

In the wake of Lance Armstrong’s admission that he used performance-enhancing drugs to win his record seven Tour de France titles, Nike took another step back from Armstrong and announced that it would stop manufacturing Livestrong-brand shoes and apparel at the end of this year. Nike, Livestrong’s main corporate backer, will continue to fulfill its financial obligations to Livestrong, the cancer foundation started by Armstrong, through 2014, but will not renew the partnership, Livestrong said.

“Considering what the foundation had been through recently and the significant changes that have occurred, of course, the foundation’s leadership had to hope for the best but expect changes like this,” said Katherine McLane, a spokeswoman for Livestrong. “Obviously, it’s a sad day, but it’s marked by the foundation’s deep gratitude to Nike.”

Nike’s decision signals an end to a partnership that began nine years ago and turned Livestrong into a marketing marvel that revolutionized the way charities raise money. Armstrong’s brand also benefited. He had rebounded from testicular cancer to race the Tour again and become a global hero to millions as a symbol of hope to those fighting cancer.