TREM2 and skin basal cell carcinoma: They revealed the Activin A-mediated dialogue between BCC and extracellular matrix (ECM)-remodeling fibroblasts in the invasive niche [123], the role of TREM2+ skin cancer-associated macrophages (SCAMs) in supporting BCC proliferation [124], and the developmental signature of fibroblasts and pericytes associated with BCCs [125].