CASP9 and head and neck squamous cell carcinoma: Our study demonstrated that depletion of PCAT-1 in HNSCC cell lines inhibits cell proliferation and induces apoptosis by i) inhibiting c-Myc and AKT1 expression, ii) activating ASK1 mediated p38 MAPK signalling, and iii) inducing Caspase 9 and PARP cleavage.