As differences in the activation of the two ROCK isoforms have been reported in cardiovascular or CNS disorders, with ROCK1 implicated as the predominant mechanism for the hypotensive effects of pan-ROCK inhibitors, one could hypothesise that there may be isoform-specific regulation of cancer cell behaviour, interactions within the tumour microenvironment and control of carcinogenesis and metastasis. The gene discussed is ROCK1; the disease is cancer.