Abstract: The present disclosure relates to cells (e.g., Chinese Hamster Ovary (CHO) cells) that are modified to reduce or eliminate the expression of certain endogenous cellular proteins, and methods of using such cells in the production of a recombinant product of interest, e.g., a recombinant protein, a recombinant viral particle, or a recombinant viral vector. These modifications were specifically chosen to generate engineered cells with desired traits in several key areas, including improved cell culture performance (e.g., higher viability and product titers).