In cancer, focal deletions are often associated with CFS; in a pan-cancer analysis [15] of 4934 cases, 70 recurrent focal deletions were reported, of which 22 were found in large genes and several genes known from CFS regions (FHIT, WWOX, PDE4D, PARK2). Here, FHIT is linked to myalgic encephalomeyelitis/chronic fatigue syndrome.