F2 and basal cell carcinoma: Preclinical studies have reported that thrombin can induce tumour growth, metastasis, and angiogenesis and that thrombin inhibitors suppress tumour growth and metastasis in some cancer cell lines.128, 129, 130 Our analyses evaluated the effect of circulating prothrombin in onset of basal cell carcinoma and, therefore, are not necessarily inconsistent with a possible role of prothrombin in driving later stages of tumorigenesis (e.g., akin to the hypothesised opposing roles of folate in cancer development and progression).131