['Expression of a large number of genes during differentiation of undifferentiated pulp cells into odontoblastic cells is still unknown, hence the aim of this investigation was to compare undifferentiated pulp cells (OD-21) and odontoblast-like cells (MDPC-23) through the assessment of cell stimulation and gene expression profiling.', 'The cells were cultured and after the experimental periods, there were evaluated cell proliferation and viability as well as alkaline phosphatase activity (ALP) and mineralization nodules. To evaluate gene expression it was used fluorescence cDNA microarray technology in addition to bioinformatics programmes such as SAM (significance analysis of microarrays). Gene expression was validated by Real Time PCR (qPCR).', 'The results showed that viability was above 80% in both cells, cell proliferation and ALP activity was higher in MDPC-23 cells and mineralization nodules were present only in the cultures of odontoblast-like cells. There were observed genes associated to odontogenesis with similar behaviour in both cell types, such as Il10, Traf6, Lef1 and Hspa8. Regions of the heatmap showed differences in induction and repression of genes such as Jak2 and Fas.'] Do undifferentiated pulp cells and odontoblast-like cells share genes involved in the process of odontogenesis?