Interestingly, it has been recently demonstrated that Axl is involved in development of resistance to a class I PI3K p110α inhibitor in HNSCC and in oesophageal SCC (OSCC) [119], suggesting a complex interplay between the Axl-dependent and PI3Ks-dependent signalling pathways in SCC. The gene discussed is PIK3CA; the disease is head and neck squamous cell carcinoma.