Immune Checkpoint Blockade in Advanced Cutaneous Squamous Cell Carcinoma: What Do We Currently Know in 2020? - Wessely, Anja; Steeb, Theresa; Leiter, Ulrike; Garbe, Claus; Berking, Carola; Heppt, Markus Vincent (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2020)