Biological systems possess robustness—the ability to maintain function under various environmental changes and fluctuations—while also exhibiting plasticity, the capacity to flexibly alter their internal states. The coexistence of robustness and plasticity is a fundamental property of living systems, yet the underlying mechanisms that enable this balance remain poorly understood. Recent advances, however, are making it possible to analyze state transitions and robustness in biological systems based on large-scale experimental data. Our team aims to elucidate the mechanisms of cellular robustness and plasticity by integrating theoretical and experimental approaches, focusing on examples such as adaptive evolution in microorganisms and developmental processes in multicellular organisms.