Hydroxyfasudil hydrochloride is widely used in research settings as a potent and selective inhibitor of Rho-associated protein kinase (ROCK). Its application is particularly significant in studies focused on understanding cellular processes such as cytoskeletal organization, cell motility, and smooth muscle contraction. Researchers utilize it to investigate its effects on vascular relaxation, making it valuable in cardiovascular studies. Additionally, it is employed in neuroscience research to explore its potential in treating conditions like stroke, spinal cord injury, and neurodegenerative diseases due to its ability to promote neuronal regeneration and reduce inflammation. Its role in cancer research is also notable, as it helps in studying tumor cell invasion and metastasis by modulating ROCK signaling pathways.