Genes involved in the regulation of fatty acid and cholesterol biosynthetic pathways. Microarray data show no significant change in SREBP-1 and -2 gene expression with IGF-1 treatment (Fig. 3A). However, when cycloheximide was added in conjunction with IGF-1 (IGF-1+CHX) to block nascent protein synthesis, both genes were activated to low and comparable extents, suggesting a similar pattern of regulation via 'derepression' (Fig. 3B). This level of 'derepression' was not seen with CHX treatment alone (data not shown). Insig2, Scap, S1p and S2p, are genes associated with SREBP-mediated lipogenesis, of these only Insig2 expression is moderately (1.6-fold) up-regulated (Fig 3C).