The PDIA1 inhibitor CCF642-34 was also tested on additional multiple myeloma cell lines with different levels of PDIA1; KMS-12-PE, RPMI 8226, and U266, and the LD50 was 165 ± 8, 292 ± 11, and 371 ± 26 nanomolar, respectively (Supplemental Figure S2A–D). Here, P4HB is linked to plasma cell myeloma.