Activation of PI3K is essential for proliferation of erythroblasts. Activated phosphotidylinositol-3 kinase (PI3K) generates phosphatidylinositol (3,4,5-triphosphate (PIP3), which serves as an anchor for multiple PH-domain containing proteins, such as phosphoinositide-dependent kinase 1 and 2 (PDK1/2) transducing signals to the protein kinase B (PKB) pathway. PKB activates mammalian target of rapamycin (mTOR) through phosphorylation of the tumor suppressor complex Tsc1/Tsc2 (tuberous sclerosis protein), which releases RAS-homolog enriched in brain (Rheb). Activation of mTOR results in phosphorylation and activation of p70S6 kinase (S6K),¹³  and hierarchical phosphorylation of 4E-binding protein (4EBP), resulting in release of the mRNA cap-binding factor eukaryotic initiation factor 4E (eIF4E). Subsequently, eIF4E can bind the scaffold protein eIF4G, which enables the formation of the eIF4F scanning complex at the cap (methyl-7-guanidine; m⁷G) of transcripts. Igbp1 has the capacity to sequester the catalytic domain of Pp2a (Pp2a_C), preventing dephosphorylation of both 4EBP and p70S6K, resulting in enhanced translation initiation efficiency.