The function of PCID2 (PCI domain containing 2, Ensembl gene identifier ENSG00000126226) is as follows. Required for B-cell survival through the regulation of the expression of cell-cycle checkpoint MAD2L1 protein during B cell differentiation (By similarity). As a component of the TREX-2 complex, involved in the export of mRNAs to the cytoplasm through the nuclear pores (PubMed:22307388). Binds and stabilizes BRCA2 and is thus involved in the control of R-loop-associated DNA damage and transcription-associated genomic instability (PubMed:24896180). Blocks the activity of the SRCAP chromatin remodeling complex by interacting with SRCAP complex member ZNHIT1 and inhibiting its interaction with the complex (By similarity). This prevents the deposition of histone variant H2AZ1/H2A.Z at the nucleosomes of key lymphoid fate regulator genes which suppresses their expression and restricts lymphoid lineage commitment (By similarity). {ECO:0000250|UniProtKB:Q8BFV2, ECO:0000269|PubMed:22307388, ECO:0000269|PubMed:24896180, ECO:0000305|PubMed:23591820}.