CA125 result can be a "false positive" or a "false negative" - in other words it does not always indicate tumor progression or regression. However, the resolution of a splenic metastatic mass on ct or mri is 100 % true positive indicator of response. I think the ct or mri studies are the best indicators of how the cancer is doing. That is why the patients are usually followed up with these tests every few months initially and then 6 months and 1 year later. We are obviously hoping to see these metastases shrinking, remaining stable or disappearing and correlating that with elevated P21 or 53 levels when patient is taking Kevetrin