Only PWM-treated myeloma cell lines can inhibit the lysis of PWM-treated, labeled myeloma cells.

Lysis of the nonmyeloma cell line K562 + PWM cannot be inhibited by myeloma cell lines. Cold-target inhibition assays were performed as described in “Materials and methods.” (A) The labeled target was COL + PWM, and unlabeled competitors were MER, MER + PWM, COL, and COL + PWM. The data represent the mean of triplicate values of 1 of 3 similar experiments. (B) The labeled target was the erythroleukemia cell line K562 treated with PWM. Unlabeled competitors were K562, K562 + PWM, MER, and MER + PWM. The data represent the mean of triplicate values from 1 of 2 similar experiments.