The authors of [2] considered the following situa tion: normal cells of the body can be transformed into the neoplastic cells (cancer), which proliferate at a high rate; the body's immune system recognizes these cells and destroys them; the outcome of this confron tation ("cell war") can be different depending on the system parameters that determine the integrated effectiveness of the immune response.The extreme complexity of the immune response was not an obstacle to attempts of researchers to its model study, which can catch only very coarsened properties of this system.The literature proposes several dozen models of the object. They are divided into point models [4,7,8,13,14], which describe the tumor growth mechanism and the immune response to the tumor, and three dimensional models, which describe not only the growth mechanism but also the spatial growth of the tumor. In the latest models, the description of the growth mechanism is significantly simplified com pared to the first models; the spatial aspect is described by cellular automates [9, 10], a simple diffusion term [3,5,11], or by the Navier-Stokes equations [12]. The growth mechanism is usually described by two to six (up to 12) equations that are similar to the equa tions of homogeneous chemical kinetics, whereas any adaptive responses of the immune are ignored.One of the first models cited in [2] was intended to describe the initial stage of the immune response to an emerging tumor [6]. This is a relatively simple dynamic model that, firstly, describes the main pro cesses in the system, and secondly, has not been funda mentally improved to date. Despite its advantages, in our opinion, it was not explored comprehensively (for example, phase portraits were not constructed) and, more importantly, all possible effects interesting for applications have not been obtained from it. In view of this, the purpose of this study was to open the potential of this model more completely give and expand possi ble biological (medical) interpretations of its behavior.One of the main methods for studying two and three dimensional models is to construct and analyze parametric and phase portraits of the system. In our case, these portraits show the areas of parametric and phase space in which a favorable outcome of the immune response to the emergence of neoplastic cells (gaining a victory of the "good" cells over the "bad" ones) can be expected. The procedure of forcing the parameters and phase variables to a favorable area is