2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/24766In this work a three-states cellular automaton proposed to describe part of a biological immune system is revisited. We obtain the dynamic critical exponent $z$ of the model by means of a recent technique that mixes different initial conditions. Moreover, by using two distinct approaches, we have also calculated the global persistence exponent $θ_{g}$, related to the probability that the order parameter of the model does not change its sign up to time $t$ [$P(t)\propto t^{-θ_{g}}$].15 pages, 5 figuresStatistical Mechanicstext