We also analysed the correlation between gene expression and immune cell infiltration levels using TIMER data and found that other than PRDX6 and HTATIP2, all other 13 gene signatures were significantly and positively correlated with tumour purity and B cell, CD4+ T cell, CD8+ T cell, macrophage, neutrophil and dendritic cell infiltration levels. This evidence concerns the gene PRDX6 and neoplasm.