In a few cases the altered genes were shown and validated by siRNA experiments to be connected with IGF-1R function, i.e. SOCS3, BCL2, and MAPK. Importantly, only a reversible resistance developed in the presence of PPP, even after long-term cultivation of both solid tumors and MM in vitro (71) (Jernberg-Wiklund, unpublished observations). The gene discussed is BCL2; the disease is Miyoshi myopathy.