Elevated CK2 activity has been associated with malignant transformation and aggressive tumor growth and overexpression of CK2 has been documented in multiple types of cancer. CK2 has emerged as a potential anticancer target and inhibition of CK2 represents a potential therapeutic strategy to target a specific molecular defect perpetuating many cancers. CX-4945 has demonstrated potent inhibition of CK2 enzymatic activity. This study will evaluate the safety, pharmacokinetics (PK), and pharmacodynamic (PD) effects of CX-4945 administered to patients with malignancies or lymphoproliferative disorders known to overexpress CK2 including advanced solid tumors, Multiple Myeloma and Castleman's Disease.