Serum lactate levels at the time of blood sampling were significantly positively correlated with TLR2 (rs 0.570; p = 0.001), TLR4 (rs 0.369; p = 0.045), IRAK3 (rs 0.569; p = 0.001), and IRAK4 (rs 0.413; p = 0.029) monocyte mRNA levels in the early phase after cardiac arrest (Fig. 3a). Here, TLR4 is linked to cardiac arrest.