Had the same question.  Sure hope cohort 4 starts by mid-April at the latest so we would have some data from it prior to ASCO.  Many think cohort 4 is the start of crunch time for tumor reduction and p21 indications and it would be nice to have some superior results from the early low dosage cohorts.

Re: p21, even if we get no great results from the tests just run, something has to be working for the patients if they are all still alive and well.  As long as trials still proceeding with no surprises, all is well.