Adaptive Immune System New and Updated Topics and Pathways. Topics with new or revised pathways in this release include Chromatin organization ( SWI/SNF chromatin remodelers ), Developmental biology ( Developmental lineage of pancreatic endocrine mid progenitor cells and Differentiation of circulating monocytes ), DNA repair ( Negative regulation of DNA double strand break response and Recruitment and ATM-mediated phosphorylation of repair and signaling proteins at DNA double strand breaks ), Gene expression ( RNA polymerase I transcription ), Immune system ( Affinity selection of immunoglobul