Adjusting for co-factors (lifetime psychopathology, psychological distress, and sustained virological response at follow-up, that is a measure of successful virus eradication), alexithymia and somatizing vulnerability independently predicted IFN-related somatization symptoms while not adverse biological events (as anemia, neutropenia, and thrombocytopenia) during the entire study period, explaining 77– 80% of their variance at both baseline and follow-up evaluations. Here, IFNA1 is linked to neutropenia.