James M. Cain was so impressed with Lana Turner's performance he presented her with a leather-bound copy of the book inscribed, "For my dear Lana, thank you for giving a performance that was even finer than I expected."
It took 12 years to adapt the explicit material (by 1940 standards) of the novel into a screenplay tame enough to comply with the Production Code prevalent at the time.
This caused a stir amongst 1940s audiences, who were shocked when it seemed clear to them that John Garfield uses his tongue in one of his kissing scenes with Lana Turner.