A pan-cancer classification based on fmrp pathway activity that informs differential prognosis and therapeutic responses

The present invention relates to methods and compositions which provide a companion diagnostic for cancer therapy. A method for identifying and stratifying a patient or group of patients with cancer as (i) being high or low for FMRP activity, (ii) having a high or low risk prognosis, and/or (iii) being a responder or non-responder to cancer therapy, and/or (iv) having high or low immune cell infiltrated tumor.