The function of an incident response team in IT is to manage and mitigate the effects of security incidents. This team is responsible for identifying, assessing, and responding to security breaches or threats quickly and effectively, minimizing damage and restoring operations. They develop and implement incident response plans, conduct forensic analysis, and provide post-incident reports to prevent future occurrences. Their role is crucial in protecting sensitive data, maintaining compliance, and upholding the integrity of IT systems within an organization.