RIPK1 and infection: Pre-treatment of A549 type II pneumocytes with the general caspase inhibitor Z-VAD-FMK (Zvad) and either RIPK1 inhibitor necrostatin-1s (Nec1s) (Fig. 1a), RIPK1 inhibitor necrostatin-5 (Nec5) (Fig. 1b), RIPK3 inhibitor GSK’ 872 (Fig. 1c), or MLKL inhibitor necrosulfonamide (Fig. 1d), all protected in an additive manner versus pretreatment with each drug alone against Serratia marcescens (Sma) infection.