Which song became synonymous with La Casa de Papel and its heists?

'Bella Ciao' is the song that became synonymous with La Casa de Papel and its heists. Originally an Italian folk song that was sung by the anti-fascist resistance movement during World War II, the song has become an anthem of resistance and revolution. In the show, the song is first sung by the robbers as a way to lift their spirits and bond over their shared struggle against the system. Later, the song is used as a symbol of resistance by the hostages and the public who support the robbers' cause.

The song has been covered by various artists and bands over the years, including Manu Chao, Chumbawamba, and Modena City Ramblers. The version used in La Casa de Papel is a remix by the Italian DJ and producer, DJ Pone.