 This paper introduces immune cell abundance identifier, imicellae, a novel method for accurately estimating the abundance of various immune cell types from gene expression data. The method was evaluated using both sequencing data and publicly available expression data, demonstrating its superior performance compared to existing methods. Additionally, the authors used imicellae to analyze immunotherapy data sets and found that the abundances of certain T cell subsets were significantly higher in responders than in non-responders. Finally, they developed a model based on imicellae results which could accurately predict the response to immunotherapy. This article was authored by Yerumiao, Cheongjang, Qianlei, and others.