PIK3CA and cancer: LSD1 regulates different signalling pathways, such as the Wnt/β-Catenin, PI3K/AKT signalling, EMT-related, Notch signalling and ubiquitin–proteasome pathway, and target proteins, such as the classic cancer suppressor star protein p53, HIFs, and immune checkpoints, in different types of cancer to mediate cancer progression.