In this investigation, we first used data from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) to do a pan-cancer analysis of PIK3CD expression.PIK3CD was significantly downregulated in 10 tumor types, including BRCA, COAD, LIHC, LUAD and LUSC (Fig. 1). The gene discussed is PIK3CD; the disease is cancer.