Abstract

As an ancillary proposition we can note that tumors are more than insular masses of proliferating cancer cells. Instead they are complex tissues composed of multiple distinct cell types that participate in heterotypic interactions with one another. There are the recruited normal cells, which form tumor-associated stroma, as active participants in tumorigenesis rather than passive bystanders. As such, these stromal cells contribute to the development and expressing of certain hallmark capabilities. During the last decades this notion has been solidified and extended, revealing that the biology of tumors can no longer be understood simply by enumerating the traits of the cancer cells but instead must encompass the contributions of the tumor microenvironment to World Cancer Epidemic.