Fig. 1

Arginase therapy is effective against immunotherapy-resistant melanoma. a CT thorax and abdominal radiographs at screening, showing extensive apical, pleural and diaphragmatic disease, in axial and coronal reconstructions and b complete remission in axial and coronal reconstructions. Radiographs were reported according to RECIST criteria. c Volcano plot of differential expression between complete responder melanoma and melanoma cohort. Red dots indicate significantly differential expression (BF > 10). Gene names shown. d Heatmap of top 30 differentially expressed genes via RNA-seq between BCT-100 responsive melanoma (BCT-Mel, n = 2 repeats, red) and control cohort (consisting of melanoma cell lines MEWO, 501_MEL and eight primary cell cultures from stage IV melanomas) as listed on the X-axis. e Expression of arginine pathway genes in patient and control samples, expressed relative to GAPDH. f Representative immunohistochemistry of patient’s tumour showing background staining (top), ASS (1:5000, dilution - middle) and OTC (1:5000 dilution bottom). Positive control staining on a neuroblastoma tumour shown for comparison. g Expression of arginine pathway enzymes in 44 samples of metastatic melanomas held with the R2: Genomics Analysis and Visualization Platform (http://r2.amc.nl)