To determine the interactions of nucleosome assembly protein NAP1L1 with LANA in KSHV-infected primary effusion lymphoma (PEL) cells, a co-immunoprecipitation (co-IP) assay was performed on the endogenous proteins from KSHV-positive, BCBL-1 and BC-3 cells. The gene discussed is NAP1L1; the disease is primary effusion lymphoma.