The soundtrack used during the Christmas scene was taken from a video of the real Paolo Macchiarini playing the piano, and was filmed by the real Benita. The video in question was featured in the Netflix documentary Bad Surgeon.
Several side characters are composites of real people. Most notably, Drs. Anders Svensson and Nathan Gamelli largely represent real-life Drs. Oscar Simonson, Thomas Fux, Karl-Henrik Grinnemo, and Matthias Corbascio.