Our studies are focused at searching and verifying usefulness of treatment response markers, with particular emphasis on radiotherapy and use of clinical material. Analyzed specimens include tissue material and peripheral blood samples. Currently, we are busy with verifying treatment response markers in both cancer tissue and stroma as well as with broadly defined analysis of free DNA. This includes both the number and presence of mutations in free DNA. We have been using the following laboratory techniques classic and quantitative PCR, DNA microarrays, HRM, laser microdissection, immunohistochemistry. The second major topic of our work concerns assessment of present and new mutations as well as gene expression in hereditary predisposition to colon cancer (Lynch syndrome, hereditary non-polyposis colon cancer).