HERC4 is downregulated in MM cells. (A) The HERC4 expression profile in 60 NCI cell lines. #1 was RPMI 8226, a typical MM cell line. These data were retrieved from GEO dataset (http://www.ncbi.nlm.nih.gov/gds/). (B) HERC4 expression in the process of MM development. HERC4 expression levels were retrieved from a DNA microarray with 99 primary bone marrow samples including normal donors, MGUS, SMM, and MM patients. (C) Selected solid-tumor cell lines and MM cell lines were subjected to IB against HERC4. (D) Primary bone marrow cells from MM patients and healthy donors were applied for the evaluation of HERC4 RNA expression by reverse-transcription PCR followed by density analysis with ImageJ software.