TLR4 and pneumocystosis: In addition, some reports have indicated that Notch signaling involves the participation of the NF-κB and MAPKs pathway [54,55], that PCP can stimulate the up-regulation of NF-κB and TLR-4 [6,13], and that Notch antagonists prevent the M1 macrophage polarization stimulated by polysaccharides [50].