Generally, the results from both softwares are slightly different but consistent. BestKeeper was used to generate SD values: the lower the SD value, the higher the gene stability. We assessed the stability of putative control genes in the developing lung at specific developmental stages to determine the most stable genes based on stability values calculated by geNorm, NormFinder and BestKeeper. The stability values were determined for each developmental stage separately for each sex and with both sexes combined. Our data demonstrate that the relative gene stability may vary throughout the developmental period. For example, in males, sno142 ranked first during the saccular stage while it was the least stable gene during the canalicular stage with geNorm and NormFinder. sno234 was the least stable gene during the saccular stage and the most stable gene during the pseudoglandular and the alveolar stages with both geNorm and NormFinder. In addition, sno251 was the least stable gene during the pseudoglandular and the canalicular stages with the three calculation methods, while it was the second more stable gene during the alveolar stage with geNorm and NormFinder. These observations are compatible with the fact that the developing lung is changing across developmental time. The use of control genes selected from multi-stage sampling would be reserved for studies extending over multiple developmental stages. Taken together, our data demonstrate the importance of choosing the most stable pair of Vorinostat endogenous control genes to adequately represent the actual biological situation. Recent studies quantifying miRNAs by qPCR in the developing lung used normalization genes known to be stable in various adult tissues. To our knowledge no study has focused on analyzing the expression stability of control genes in the lung by sex and over developmental time. Our study analyzes the stability expression of five endogenous control genes through lung development and by sex. Our data demonstrate that ranking of genes according to expression stability is influenced by sex and developmental age when geNorm, NormFinder or BestKeeper is used. We present for the first time pairs of control genes for specific developmental stages as well as for the entire period extending from the pseudoglandular to the alveolar stages of lung development, which corresponds to the most studied period. These findings will be helpful for studies of miRNA involvement in lung development and neonatal diseases related to preterm birth. Metabolomics is a robust bioanalytical tool for the comprehensive analysis and monitoring of plant metabolome. However, its application for monitoring the regulation of the global plant metabolism in response to biotic stresses is still in its infancy, receiving increasing attention.