Molecular variability across individual cells is an intrinsic feature caused by both deterministic and stochastic mechanisms. Gene expression noise, given by stochastic effects in mRNA synthesis, is a major contributor of molecular variability. During cell differentiation, stem cells express early differentiating genes in a random way, promoting cell bias to commit into a particular cell lineage. However, it is still not clear which is the role of gene expression variability in cell fate decision. To gain insights into this question, I am performing in silico analyses of single-cell transcriptomic data. I aim to develop a computational approach for reliable quantification of gene expression variability and to further characterize how this variability changes across differentiation trajectories.