Two sets of handwritten lyrics from late rapper Tupac Shakur that were penned while he was behind bars are set to go on the auction block.

The manuscripts are part of a Sotheby’s Rock & Pop exhibition sale in London on Sept. 29 and could garner £30,000 to £50,000 — as much as nearly $80,000, according to published reports.

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Tupac wrote the lyrics for “Ambitionz Az a Ridah,” which appeared on his fourth album "All Eyez on Me" while serving time for sexual assault.

The rapper was released from prison in October 1995 and his album — which was made immediately after — went on to become a best-selling record for Tupac and earn him critical acclaim.

Just months later, in September 1996, Tupac was fatally shot in Las Vegas.

We are delighted to have this item in our sale, it's a really unusual item," said Gabriel Heaton, Sotheby's specialist in books and manuscripts told The Mirror.

"It is the most significant manuscript item that has come to market.

"He [Tupac] is a fixture of enormous popularity and great cultural significance, so we are confident there'll be a lot of interest."