APP and neoplasm: We next examined the association between HPS expression and APP specifically within purified immune lineages (GSE24759),31 which revealed a significant and strong positive correlation between HPS expression (originally identified from bulk tumours; figure 4B–C) and APP signalling in mature antigen presenting cells (APC) (online supplemental figure 5E; Pearson’s correlation r=0.89974, p=1.36×10−11).