"CDK12-mutant tumors were completely unique from all other prostate cancer subtypes, including those with MMR mutations. CDK12-mutant tumors expressed a unique set of genes, and had a unique pattern of mutations, including a high level of mutations that altered the form of proteins. This finding led DR. Chinnaiyan and team to hypothesize that these tumors may be visible as “bad apples” to the immune system – and that immunotherapy may work for these patients."
EDIT: About 6% of men with advanced PCa have the CDK12 mutation.