TNF and neoplasm: In an in vivo model of ovarian cancer, C. acnes infection by intratumoral injection led to an upregulation of proinflammatory cytokines IL-1-beta (IL-1β) and TNF-α and activation of the Hedgehog signalling pathway, which can modulate the tumour immune microenvironment through driving tumour-associated macrophage proliferation, T-cell activation, and upregulation of PD-L1 [70].