Kendrick Lamar has always made his admiration for Tupac Shakur known.
In fact, he was initially going to title his To Pimp A Butterfly album Tu Pimp A Caterpillar. (Which would be abbreviated as TUPAC.)
Pac died 19 years ago to the day in Las Vegas, and there's a special message from K.Dot on Tupac's offical website:
What does Tupac mean to you?