Concentrations of the proinflammatory cytokines IL-1β, IL-6, and TNF-α in milk of quarters infused with either MDP, S. aureus LTA, or LTA plus MDP from the time of infusion (time zero) to 96 hpi. Data are from 11 cows (median values and interquartile ranges). *, significantly increased concentration relative to that at time zero (P < 0.05); $, significant difference between LTA plus MDP and LTA or MDP alone (P < 0.05).