FIGURE 1.

Phosphorylation status of RSK2^Ser227 in patient (Pt.)‐derived mantle cell lymphoma (MCL) tissues and MCL‐derived cell lines. A, Hematoxylin‐eosin (HE) and immunohistochemical staining for cyclin D1 (CCND1) and phosphorylated (p)‐RSK2^Ser227 in tumor biopsy specimens from patients (Pt. Nos. 1‐5) with MCL. Cytoplasms of lymphoma cells were positive for CCND1 and p‐RSK2^Ser227. B, Expression patterns of total RSK2, p‐RSK2^Ser227, p‐RSK2^Tyr529, ERK, p‐ERK, AKT, and p‐AKT^Thr308 examined by Western blotting in five MCL‐derived cell lines and normal lymphocytes. β‐Actin (ACTB) was used as the internal control. RSK2^Ser227 was phosphorylated regardless of the activation status of RSK2^Tyr529, ERK, and AKT in all five cell lines