An siRNA screen targeting 51 apoptosis-related genes revealed that HRK (Harakiri, BCL2 Interacting Protein), BIRC5 (Baculoviral IAP Repeat Containing 5), BCL2L1 (B-cell/Lymphoma 2 like 1), BCL-10 (B-cell/Lymphoma 10) and CRADD (CASP2 And RIPK1 Domain Containing Adaptor With Death Domain) were essential genes in the JJ012 chondrosarcoma cell line (Figure 1a). The gene discussed is CRADD; the disease is chondrosarcoma.