This reports the opposite of what we thought regarding tumor mutational burden. A high tumor mutational burden in other cancers would make the tumor more likely to respond to immunotherapy but that did not work out with Glioblastomas. This study says that a very low tumor mutational burden for glioblastomas results in a better response with immunotherapies. They also release some new data from the PVSRIPO trial showing impressive results for recurrent Glioblastoma patients with less than the median tumor mutational burden. Of 21 patients in the trial, 10 in the high TMB group and 11 in the Low TMB group, at the 3 years point after treatment 3 of the patients in the low TMB group were alive, while none in the High TMB group were alive. These 3 patients were still alive at the end of the trial, one at 36 months, one at 60 months and one at 96 months! It is a small number of patients, but I would consider this trial if I had a low TMB. TMB is usually reported on your pathology report.