In Arabic, the equivalent of the term "Roll-in phase" in a clinical trial is "مرحلة البدء قبل التصادف" or "مرحلة الدخول قبل التصادف." This phase refers to the initial stage of a clinical trial where a small number of patients, usually three individuals, receive treatment before the randomization process begins. In this phase, these patients are treated and monitored to ensure that the necessary conditions for participating in the trial are met and that no unexpected adverse effects result from the treatment. The Roll-in phase is conducted to improve the trial protocols and ensure the safety and suitability of the selected patients before they enter the main randomization phase of the trial, where they are assigned to different treatment groups to evaluate the efficacy and safety of the investigational drug or intervention.