Transcription coactivator that plays a role in the regulation of cell expansion in leaf and cotyledons tissues (By similarity). Component of a network formed by miR396, the GRFs and their interacting factors (GIFs) acting in the regulation of meristem function, at least partially through the control of cell proliferation (By similarity). GIFs are involved in the positive regulation of cell proliferation of lateral organs in a functionally redundant manner. Interacts with GRF1. Predominantly expressed in shoot tips containing the shoot apical meristem (SAM) and flower buds. Also expressed in mature flowers. Belongs to the SS18 family.