Involved in the modulation of the mitochondrial apoptotic pathway by ensuring the accumulation of cardiolipin (CL) in mitochondrial membranes. The TRIAP1:PRELID1 complex probably functions as a PA transporter across the mitochondrion intermembrane space to provide PA for CL synthesis in the inner membrane (By similarity). May be involved in hematopoiesis during avian development. a 1,2-diacyl-sn-glycero-3-phosphate(in) = a 1,2-diacyl-sn-glycero-3-phosphate(out) Forms a complex with TRIAP1 in the mitochondrion intermembrane space. Expressed within the blood islands and in the liver. Restricted to developing blood cells.