JAK1 and neoplasm: JAK1 expression was negatively correlated with tumour purity (r = − 0.309, P = 5.34e−12) and significantly positively correlated with infiltrating levels of B cells (r = 0.224, P = 8.82e−07), CD8+ T cells (r = 0.26, P = 9.26e−09), CD4+ T cells (r = 0.517, P = 7.50e−34), macrophages (r = 0.405, P = 2.92e−20), neutrophils (r = 0.522, P = 1.36e−34), and dendritic cells (r = 0.5, P = 2.20e−31) (Fig. 3).