Under natural conditions (non-tumor cells), the mechanisms of proliferation, differentiation, apoptosis (programmed death), intercellular communications harmoniously interact. All this contributes to the implementation of specific cell functions and cell populations in unity with other cells at the level of the whole organism. With the development of pathological processes, the harmony of physiological processes is disturbed. For example, the inhibition of immune reactions is accompanied by the development of carcinogenic processes. Uncontrolled activation of proliferative processes promotes an abnormal increase in the number of cells, which threatens the development of the tumor process. Therefore, the factors that participate or "intervene" in the processes of cell proliferation or death under certain conditions begin to play a key role in the development of tumors. Please study the two manuscripts in Attachment on the role of PD-L1 in the processes of carcinogenesis.

There might be truth in that statement. In our experience inhibition of LINE-1-encoded reverse transcriptase (RT) or repression of LINE-1 expression antagonize cancer progression as assessed in animal models and, more recently, in a phase II human trial. In addition, the unusual features of the nacked mole rat would confirm this view. The LINE-1 component is significantly reduced in the genome of these animals compared to other species and its expression is fully repressed. Interestingly these animals are highly resistant to both spontaneous cancer and experimentally induced tumorigenesis. I am convinced that LINE-1 activity plays a major causative role in cancer onset and progression.

I am curious to learn about the source of the statement you mentioned.