We know that The Godfather films draw knowledgeably and extensively on classic 30s gangster films for their structures and iconography. But watching Little Caesar recently I was struck by how closely and directly the influence of Little Caesar can be seen in The Godfather and The Godfather II. Here are but two examples:
On the left, the killing of Tony Passa in the Church Steps in Little Caesar and on the right the finale of killing during the baptism scene in The Godfather.
The funeral sequence in Little Caesar on the left closely resembles the festival of San Rocco scene in The Godfather: Part II where Vito Corleone plans to murder Don Fanucci.