'Blow' Inspiration George Jung Dead at 78

George Jung -- the prolific cocaine smuggler portrayed by Johnny Depp in the movie "Blow" -- has died ... TMZ has learned.

Sources close to the situation tell TMZ ... George died Wednesday morning at home in the Boston area. The cause of death is currently not known, though he had recently been experiencing liver and kidney failure.

We're told he had been in home hospice care since this past weekend and died with his girlfriend, Ronda, and friend, Roger, by his side. We're told he will be cremated.

George's Twitter account tweeted a quote from the film Wednesday, “May the wind always be at your back and the sun upon your face, and the winds of destiny carry you aloft to dance with the stars. 1942-2021."

"Boston George," as he was known, served 20 years in prison for running drugs. He was released in 2014, but ultimately landed back behind bars just 2 years later for violating his parole by failing to inform his parole officer he would be hitting up San Diego.

He was famous for being part of the Medellin Cartel and helping Pablo Escobar smuggle planeloads of cocaine into the U.S. That was a big deal because, at the time, Escobar's cartel was responsible for distributing 80% of the world's cocaine -- and about 15 tons of blow reportedly came into the U.S. per day ... for a weekly haul of $420 million.