What are some types of tumors and their causes?
Historically cancer has been classified according to its tissue of origin - lung cancer, skin cancer, etc.
But modern oncologists and molecular biologists no classify different types of cancers according to their genetic causes no matter what tissue they originate in.
In that context, one type of cancer is caused by mutations in the epidermal growth factor receptor (EGFR) gene.
Mutations in this particular signalling pathway tend to produce similar cancers in glandular epidermal tissues - for example, certain types of breast cancer, parotid and salivary cancers and various epidermoid lung cancers with this driving mutation are all basically the same disease showing up in different tissues depending on where the original mutation started.