The national anthem protest went to a whole other level in the NFL's Thursday Night Game between the San Francisco 49ers and Oakland Raiders when a cheerleader decided to take a knee and join the protest.

What's the background?

The 49ers were the origin of the controversial protests that have engulfed the NFL in a public relations firestorm, when former quarterback Colin Kaepernick began taking a knee during the performance of the national anthem before each game.

The protests quickly spread to other players of NFL teams, but it really exploded after President Donald Trump excoriated the players' protest during a Pennsylvania rally and called for their firing.

“Wouldn’t you love to see one of these NFL owners when somebody disrespects our flag, to say get that son of a b**ch off the field right now?” he said to great applause.

What else?

Photos of the unidentified cheerleader were shared on social media over the unique new expression of protest against allegedly racially-based shootings of African-American males in the United States.

The other 49ers cheerleaders can be seen standing during the performance, but one can be seen taking a knee.

Kaepernick has filed a grievance against the NFL, and later signed on to a million dollar advertising contract with Nike corporation. The ad campaign purposely praised him for his national anthem protest, which inspired even more public outcry against the shoe company.

Here's another photo via @GatorLenny of the #49ers cheerleader taking a knee during National Anthem at #TNF game vs. #Raiders. https://t.co/lG9KpHBls0 #NFL pic.twitter.com/SA0sXaQZ04

— Kristofer Noceda (@krisnoceda) November 2, 2018

Here's a news video of a closer look at the kneeling cheerleader: