Growth of the CML cell line, K562, is suppressed by 2-5–antisense directed against bcr-abl mRNA. Cells were without treatment (⊞) or with twice daily treatments with 2 μmol/L of (A) SpA₄-anti-bcr (•), anti-bcr (⧫), SpA₄-(M5)anti-bcr (▪), or SpA₂-anti-bcr (▴) or in (B) of SpA₄-anti-b3a2 (□), anti-b3a2 (▵), SpA₄-anti-b2a2 (○), or SpA₄-(M6)anti-b3a2 (◊). Cell numbers are the average obtained from duplicate wells.