FAP and squamous cell lung carcinoma: In addition to its effects via the PI3K/AKT pathway, Jia et al. further discovered that the SHH-FAP axis promoted cell growth, adhesion and migration potentially via the SHH/GLI signaling pathway in lung squamous cell cancer (SCC) cell lines, since only inhibitors of PI3K and SHH suppressed the increased motility of FAP-expressing cancer cells [56].