Analysis of gene expression by quantitative real-time RT-PCR in indirectly co-cultured CCD-1068SK fibroblasts revealed that tumour cells did not influence the expression of COL1A1, COL1A2, CCN2 or Smad7 when compared to fibroblast monocultures (Figure 1D). The gene discussed is COL1A2; the disease is neoplasm.