Tissue-specific cancer paradox and mutation rates

Some genes have ubiquitous expression patterns in an individuals cells, thus a paradox exists whereby mutations in such genes are only strongly associated with cancers of specific tissues. As these genes are ubiquitously expressed in the bodys cells and thereby have functions in -potentially- all tissue types, then surely their resulting defects would manifest as cancers in all tissues?\n\nWe hypothesize that the different susceptibility to mutations could explain the tissue-specific paradox for cancer.