Familial Mediterranean fever (FMF) was initially described in 1945 as “benign paroxystic peritonitis” in patients displaying recurrent peritonitis and periodic short fever attacks: this is the most common among all HAIDs and the first one with the causing gene identified in 1997, named MEFV, which encodes a 781-amino acid protein, wherever known as pyrin [7]. Here, MEFV is linked to peritonitis.