Brown preadipocyte proliferation is one of the crucial events during brown adipose tissue recruitment in response to cold exposure and relevant physiological challenges [1]. β1-adrenoceptor signalling through cAMP has been revealed as the hypertrophic effector in norepinephrine-stimulated cell proliferation of primary cultured brown preadipocytes [2]. Proto-oncogene regulation is implicated in this recruitment process as seen with the discovery of mitogenic proteins regulation in a β-adrenoceptor dependent manner, including the angiogenic protein VEGF [3] and the proto-oncogene c-fos [4]. To explore functional signalling proteins involved in this process, a microarray study was carried out to identify candidate genes possibly involved in cAMP induced cell proliferation. We have further examined these candidate gene expression with reverse transcriptase quantitative PCR (RT-qPCR). NMRI mice weighing around 13-15 g were sacrificed with CO2 euthanasia followed by cervical dislocation, as approved by the Northern Stockholm Animal Ethics Committee. Brown adipocyte precursors are separated from the interscapular, cervical and axillary brown adipose tissue depots, as described by Néchad et al.[5]. To validate NE regulation of gene expression, RNA was isolated from newly cultured brown preadipocytes, which were stimulated with norepinephrine at a series of time points: 1 h, 2 h, 4 h and 8 h. RT-qPCR was used for gene expression analysis, and 8 of the 19 genes are validated as upregulated with the stimulation of 1 μM of norepinephrine, with the most prominent effect at 2 h or 4 h for most genes. To check the effect of cAMP on the expression of these genes, RNA isolated from samples with 1 μM of forskolin stimulation for 4 h was used for RT-qPCR analysis. 18S was used as endogenous control for gene expression analysis and the expression level of all other genes were expressed as the percentage of 18S. Data shown in table 1 are mean ± SEM, compared with Student t-test. * p<0.05; ** p< 0.01. Here we report that 8 out of 19 genes derived from microarray study has been confirmed with RT-qPCR to be upregulated in brown preadipocytes at mRNA levels with both NE and FSK stimulation: Adora 2B, ARHGAP8, Fgf18, Gpr133, Prr5, Tmem37, Twist 2 and Ube2S. We propose that these protein-encoding genes are possibly functionally involved in cAMP-promoted cell proliferation.