TLR4 and systemic sclerosis: Indeed, for the first time, cells highly positive for TLR4 (M1 marker) and M2 markers were detected in the same areas (alveoli) of SSc-ILD samples, strongly suggesting the possible presence of hybrid TLR4+M2 macrophages (CD68+CD80-CD86-TLR4+CD163+CD204+CD206+cells) as a prevalent population at least in SSc-ILD.