Method for increasing expression of active tumor necrosis factor receptor family member-Ig fusion proteins

A method for increasing expression of active tumor necrosis factor (TNF) receptor family member-Ig Fc fusion proteins and minimizing expression of inactive TNF receptor family member-Ig Fc fusion proteins comprising culturing a mammalian host cell transformed with DNA molecule encoding a desired TNF receptor-Ig fusion protein in a mammalian cell culture having a minimum temperature of about 27° C. to a maximum temperature of less than or equal to 30° C., wherein the transformed host cell is first cultured at a temperature of about 33° C. to about 37° C. for a period of time sufficient to allow growth of said host cell, and wherein the active TNF receptor family member is involved in immune regulation and comprises 2-4 copies of canonical TNF family cysteine-rich domains.