LINC00511 (54) and miR-27a-3p [targeting the FOXO1/PI3K/AKT pathway (55, 56)] regulate tumour stem cell properties, whereas exosomal circRNAs [such as bile-derived CCA-circ1 (57)] and circNFIB [through miR-412-3p/PIK3R3 inhibition of metastasis (58)] can serve as molecular subtype biomarkers. This evidence concerns the gene PIK3CA and neoplasm.