Abstract: The invention relates to methods and kits for detecting the likelihood that a subject has cancer, e.g., squamous cell carcinoma, by assaying the expression levels of tumor associated genes. More specifically, the expression levels of nucleic acids or proteins can be assayed in the tumor associated genes, e.g., beta-2 microgobulin (B2M) and cytochrome p450 1B1 (CYP1B1). The expression levels compared to standards can be indicative of the likelihood a subject has squamous cell carcinoma. For example, over-expression of B2M and under-expression of CYP1B1 can be indicative of the likelihood a subject has squamous cell carcinoma. Also, over-expression of B2M and over-expression of CYP1B1 can be indicative of the likelihood a subject has a precancerous squamous cell disorder. The expression levels of B2M and CYP1B1 can also be repeatedly assayed to monitor the progression of a squamous cell neoplasia.