Abstract: The present invention provides a process for characterizing a glatiramer acetate related drug substance or drug product comprising the steps of: a) obtaining a batch of the glatiramer acetate related drug substance or drug product; b) contacting mammalian cells with an amount of the glatiramer acetate related drug substance or drug product of step a); and c) i) determining the level of expression of at least one gene selected from the group consisting of ABCF2, ABI2, ACP6, AFG3L2, ALMS1, ARPC4, CALM3, CCDC64, CD84, CDC6, CHAF1A, CLU, COX11, DLGAP1, DTX4, FAM49B, FHL1, FNTB, GYPC, HFE, IL10, LPHN1, NACA, OLAH, PATZ1, PDK1, POLI, REEP5, RPL5, RPS6KA2, SEC31A, SETBP1, SNRPA1, SYNCRIP, TNFSF9, TOMM40, TPM1, TSHZ1, TSPAN13, UBAP2, VAV3, VDAC2, and ZFAND6; ii) determining the level of expression of at least one gene selected from the group consisting of BIRC3, CCL24, CCR1, CISH, CSF1R, CX3CR1, CXCL10, HSPD1, ICAM1, IL1B, IFNGR1, IL27, IL2RG, IL7R, IL1RN, MMP1, MMP9, MMP14, PGRMC1, PRDM1, CARD15, CCL2, CCL5, CD14,