One of the most challenging aspects of oncology is detecting tumors as early as possible. The earlier cancers are found, the earlier patients can be treated, and consequently, there is a greater chance of success and survival. The molecular events that occur during the transformation of normal tissues into cancerous tissues happen very slowly and can last for years or even decades before they become noticeable. Therefore, our idea was to propose that a “biological thermometer of the tissue” would be able to detect these changes from the earliest stage. Macrophages are cells of the immune system that are present in virtually all tissues, even before birth. They have distinct characteristics and functions, and some of these macrophages are called “resident” macrophages. The project therefore proposes to investigate the mechanisms by which resident macrophages detect tumor events in tissues, including how, when, and where these events occur.