Decoding Immune Regulation: From Genetic Variation to Mechanism Through Single-Cell Genomics.

Immune cell states are not fixed. Rather, they emerge from dynamic transcriptional programs shaped by genetic variation, cellular context, and gene regulatory networks (GRNs). Single-cell and multi-omic technologies now enable population-scale immune profiling across molecular layers, revealing that cell-to-cell transcriptional variability is a functional feature that diversifies immune responses. Distribution-aware and tensor-based analytical frameworks capture this variability beyond mean expression, resolving coordinated gene programs across cell types, individuals, and conditions. Integrating human genetics with single-cell genomics demonstrates that genetic effects on gene expression, splicing, and chromatin accessibility are highly dependent on cell type, activation state, and differentiation trajectory. These variant-level signals converge on GRNs in which key transcription factors orchestrate context-dependent immune programs. High-throughput perturbation screens enable scalable functional validation of these networks, linking genetic variation to cellular function. Together, these integrative approaches translate molecular discoveries into clinical applications, from patient stratification to therapeutic target prioritization. Emerging spatial multi-omics and