Colin Kaepernick knows a thing or two about defiance.

After kneeling for the national anthem while playing for the 49ers in 2016, Kaepernick drew the scorn of a huge swath of Americans and football fans alike, including President of the United States Donald Trump, who called him a "son of a b---h."

Hip-hop icon and entertainer Dr. Dre, who starred in HBO's "The Defiant Ones" chronicling his career alongside prolific record executive Jimmy Iovine, shared an Instagram post on Sunday showing him taking a knee alongside Kaepernick, with a simple caption.

[RELATED: Kap's 49ers exit to be featured in new Disney docuseries]

Kaepernick's choice to kneel was misunderstood by many, and has kept him out of the NFL since he opted out of his 49ers contract in March of 2017. On NBC Sports Bay Area's "Race In America: Candid Conversations," former NFL star Charles Woodson spoke about how Kaepernick's protest made him reconsider the messaging behind the national anthem.

"Interestingly, then when Colin knelt, then all of a sudden," Woodson said. "When things happen you start doing a little research on things. So then you start researching the National Anthem and what it actually stood for when it first was written, and now you’re like, hold on, I can see his point now.  So now, you’re thinking to yourself, Okay, this is what Colin Kaepernick is kneeling for, I absolutely agree with that."

 

Kaepernick held a controversial workout in Atlanta that originally was endorsed by the NFL, but after changing locations he ended up having just a few teams show up. There has been rumored interest in the signal-caller from NFL clubs, but he remains a free agent.

Whether he's back in the NFL or not, Kaepernick isn't stopping trying to spread his message and fight against system racism and police brutality in the United States.

[RACE IN AMERICA: Listen to the latest episode]