Based on limited published evidence, TIMM23B is a translocase component that may participate in translocation of transit peptide-containing proteins across the mitochondrial inner membrane as part of the PAM complex. TIMM23B functions in protein import into the mitochondrial matrix and likely serves as a transmembrane protein transporter within the TIM23 mitochondrial import inner membrane translocase complex 1. Expression of TIMM23B is regulated by the GABP transcription factor, suggesting its involvement in coordinating mitochondrial biogenesis with protein import capacity 1.