In the present pilot exploratory case series, we sought to evaluate interleukin (IL)-2 and suppressor of cytokine signaling (SOCS)-1 expressions in the peripheral blood mononuclear cells (PBMCs) of patients suffering from severe ovarian hypertimulation syndrome (OHSS), and to examine whether their expressions differ when compared to PBMCs originated from normal early pregnant women (without OHSS). Here, IL2 is linked to ovarian hyperstimulation syndrome.