Achievement of durable molecular remission after syngeneic HSCT for treatment of MM in patient A. (A) Levels of serum monoclonal protein (g/dL) become undetectable by 1.5 months after HSCT. Arrows indicate the time points screened by protein microarray. Vertical dashed line indicates time of syngeneic stem cell infusion. (B) Expression of transcripts containing the IgH sequence unique to patient A's tumor is detectable by quantitative real-time PCR in BMMCs (black squares and solid line) and PBMCs (gray squares and line) before syngeneic HSCT, but is undetectable beginning at 24 months after HSCT. Values shown are tumor-specific IgH transcripts normalized to GAPDH transcript expression. “Undetectable” indicates samples with acceptable GAPDH values but absent tumor-specific IgH transcript expression.