Response to Vermorken et al - Curcumin and free light chains We thank Vermorken et al. for their interesting comments. As suggested by Hutchison and Landgren [1], the relationship between chronic inflammation and cancer is well established, although not fully understood. Measurement of inflammatory cytokines provides clinicians with a valuable tool to use across a number of clinical settings. These authors hypothesize that measuring polyclonal free light chains (FLCs) in the serum might gain new insight into the activity of the adaptive immune system potentially allowing FLC measurement to serve as a novel clinically relevant biomarker. c-reactive protein (CRP), measured as a marker of inflammation, reflects only the activity of the innate immune system. Vermoken et al. have suggested that absolute levels of FLCs rather than their ratio may be potential biomarkers of immune stimulation and inflammation [2]. Currently, only one commercial assay is available for the measurement of serum FLCs. The assay, Freelite, consists of two assays—one to measure K FLC's and the other to measure L FLC's. One of these measures is an assessment of monoclonal FLCs [involved FLC (iFLC)] and the other is an assessment of polyclonal FLC's [uninvolved FLC (uiFLC)]. In our study [3], FLC was monitored as a marker of response to curcumin. Curcumin has been known for centuries in India as an anti-inflammatory agent and it is possible to speculate that the observed response to curcumin might be associated with an anti-inflammatory effect. We are, unfortunately, not in possession of data on IL-6, CRP, or erythrocyte sedimentation rate (ESR); however, we can elaborate on the findings of the uiFLC response. From Table VII (a and b—see Supporting Information on line material), it can be seen that in patients who had an abnormal ratio at baseline (Table VIIa), at both the 4g and 8g dose of curcumin, all three markers of FLC response (i.e., rFLC, dFLC, and iFLC) decreased. However, the uiFLC increased in response to curcumin at both doses with this increase reaching significance at 8g. This data is suggestive of a decrease in the number/activity of abnormal monoclonal secreting cells and a concomitant increase in the normal polyclonal secreting cells/activity. Patients with a normal ratio at baseline (Table VIIb) show a smaller response in all measured parameters (except the iFLC at 8g) at both doses. From these findings, it can perhaps be suggested that patients with an abnormal ratio at baseline may be the subgroup who could benefit from curcumin treatment. Terry Golombick* , Terrence Diamond* , Arumugam Manoharan* , Raj Ramakrishna* , * Department of Endocrinology, St George Hospital, Sydney, Australia, Southern Sydney Haematology, Kogarah, Sydney.