Study of drug resistance of MOLP8/R cell line to immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs). Both cell line MOLP8 and MOLP8/R are treated for 48 h with the different molecules used in the multiple myeloma (MM) treatment, carfilzomib (Car), bortezomib (Btz), pomalidomide (POM), and dexamethasone (DEX). MOLP8 curve is represented by black dotted line and MOLP8/R curve is represented by a black full line. MOLP8/R cell line is resistant to PIs with resistance index (IR) (IC50 MOLP8/R/ IC50 MOLP8) 60 for Car (a); IR to Btz 2.14 (b). In addition, MOLP8/R cell line is resistant to the IMiD tested, POM, with an IR of 2.8 (c), whereas the MOLP8/R cell line is sensitive to DEX (d). * p < 0.05, ** p < 0.01 and *** p < 0.001.