"The Hallmarks of Cancer" is a seminal article by Douglas Hanahan and Robert Weinberg that was peer-reviewed and published in the scientific journal Cell, first in 2000. later on, in 2011, these two scientists published an update of the article, adding the proposal of new hallmarks that are present in  tumorous cells. The purpose of the article by these two scientist was to join together all the traits, which they called hallmarks, or reference points, that are common to tumorous growth. As such, they proposed a group of five traits initially in the 2000 version: self stimulation of growth in cancerous cells,  resistance to inhibitory signals, resistance to apoptotic signaling, capacity to replicate without limits, stimulation of growth vessels ans finally tissue invasion and metastatsis. In the 2011 update, these scientists added another set of hallmarks that they found, were common to cancerous growth: first, they sport abnormal metabolic processes and they are able to evade the immune system. In two sub-hallmarks, they also found that it is common for these tissues to show genome instability and inflammation processes.
On the plus side of the article, one of its biggest strengths is that it puts together and synthezises knowledge and research that has been acquired throughout the years. Basically, it simplifies and summarizes decades of research on tumors, how they begin, what characterizes them, how the body responds to them, why are they so devastating and sometimes unstoppable, among other things. And it summarizes in simple points common characteristics of all types of cancer that will help medical professionals, and other scientific researchers to push through for better, and more focused therapies.
However, the conclusion and the proposals made in the article have also received criticisms from the scientific community. First, some scientists say that these traits that are presented as common for cancer, are also present in bening tumors, which would make the identification of tumorous cells through the acknowledgment of these traits, basically erroneous. According to these criticisms, only two of the total of hallmarks presented in the article are actually unique to cancer: the capacity to metastasize and invade. The second criticism has been that there is still not enough evidence to point to the accuracy of the traits that are presented on the article as definitive descriptors of a cancerous tumor. In fact, on an article in 2013 in the Journal of Biosciences it was argued that some of the traits proposed in the original article of Hanahan and Weinberg are typical of the cellular level, and cancer is basically a disease that appears at the tissue, not merely cellular, level.
