Deletion of actA causes a 1000-fold LD50 increase of Lm via prevention of bacterial intercellular spread and, hence, systemic dissemination of infection, and additionally via promotion of autophagy (Flickinger et al., 2018; Radoshevich and Cossart, 2018; D’Orazio, 2019; Chávez Arroyo and Portnoy, 2020). The gene discussed is ACTA1; the disease is infection.