New and Updated Topics and Pathways. Topics with new or revised pathways in V78 include Disease ( Defective HDR through homologous recombination (HRR) due to BRCA1 loss of function and Defective HDR through homologous recombination (HRR) due to PALB2 loss of function ), DNA repair ( Alkylating DNA damage induced by chemotherapeutic drugs , Drug-induced formation of DNA interstrand crosslinks , and Reversible DNA damage induced by alkylating chemotherapeutic drugs ), DNA Replication ( Assembly of the ORC complex at the origin of replication ), Sensory Perception ( Olfactory signaling and Sensor