HS201, a novel photosensitizer made of VP (Novartis Pharmaceuticals, Basel, Switzerland) tethered to an Hsp90 small molecule inhibitor (HS10), was used for in vitro and in vivo imaging and PDT. HS201 was developed and supplied by Haystead Lab (Department of Pharmacology and Cancer Biology, Duke University) as previously described.23 (link) Anti-PD-L1 antibody (clone; 10F.9G2) was purchased from Bio X cell (New Hampshire USA) and used for animal treatment. Annexin V-Allophycocyanin was purchased from BD Biosciences (California USA) and 7-AAD from Beckman Coulter Inc. (California, USA). Detailed information of antibodies used for flow cytometry is shown in online supplemental methods.