Abstract <p>Igor Viktorovich Mizgirev, PhD, senior researcher of the Petrov National Medical Research Center of Oncology of the Ministry of Health of the Russian Federation provides a feedback on the series of articles published in the journal <i>Uspekhi Sovremennoi Biologii</i> of the Russian Academy of Sciences in 2024, in which he notes that the concept of <i>carcino-evo-devo</i>, developed by professor A.P. Kozlov over several decades, represents a new approach to understanding the possible role of pathological processes in the evolution of living organisms. This approach is based on the idea of hereditary tumors with small malignant potential (benign and malignant in the early stages of progression), as a kind of testing grounds, where new genes that have arisen in the course of evolution are able to be expressed in excess cell masses, and, eventually, lead to the formation of new types of cells, tissues and organs.</p>