Scientists discover what triggers allergic reactions to cats

The video explains that cat allergies are primarily caused by the Fell D1 protein found in cat saliva. This protein can trigger an allergic response, which is intensified by the presence of the environmental bacterial toxin LPS. LPS contaminates Fell D1 and activates the toll-like receptor 4 (TLR4), a crucial protein in the innate immune system. A drug was developed to inhibit the TLR4 response, effectively blocking the effects of the cat dander protein on human cells and preventing an inflammatory response.

What is the role of the Fell D1 protein in the context of cat allergies?

What was the effect of the drug used to inhibit the TLR response?