HRAS and head and neck squamous cell carcinoma: To support this hypothesis, a phase II clinical trial in patients with recurrent and/or metastatic head and neck squamous cell carcinoma (HNSCC) showed that HNSCC patients with H-Ras mutations had a 55% objective response after receiving tipifarnib.335 Another phase II clinical trial in advanced refractory uroepithelial cancer patients with H-Ras mutations also found that response was observed in 5 out of the 12 evaluated patients after treatment with tipifarnib.336 For other tumours, FTIs in combination with other treatments can improve treatment efficacy to some degree.