Pyk2 is highly expressed in MM. (A) Expression level of Pyk2 is significantly increased in MM patients (both smoldering MM and newly diagnosed MM) compared with healthy subjects (GSE2658). (B) Conversely, the FAK expression level is decreased in MM patients. (C) Expression of Pyk2 in BM biopsy specimens from MM patients (n = 14) and healthy donors (n = 6) was detected by immunohistochemistry staining. Three representatives in each group are shown (×20; ×100). All MM patients present with higher Pyk2 expression compared with healthy individuals. (D) Pyk2-positive cells in immunohistochemistry staining slides were quantified using ImageJ software. Three random fields at ×20 magnification were analyzed. (E) Based on analysis of the CCLE database, the copy numbers of genes harbored in the region from 8p21.1 to 8p22 are shown in the heatmap. U266 has significant loss of gene copy numbers, reflecting its 8p21 instability. (F) Pyk2 gene copy-number status of 27 MM cell lines enrolled in the CCLE database. (G) Based on analysis of the CCLE database, the Pyk2 mRNA level in MM cell lines is associated positively with its copy number (r = 0.7856; P = .032). (H) Pyk2 is expressed differentially in 6 MM cell lines using immunoblotting. Note that U266 cells express low to absent expression of Pyk2. NBM, normal bone marrow; SMOLD, smoldering MM.