Reduced NOD1 expression in sarcoidosis patients may impair autophagy induction and affect the supportive role of autophagy for intracellular bacterial killing, leading to enhanced intracellular survival and persistence of P. acnes. To address this possibility, these same experiments should be performed using human macrophages and epithelial cells from subjects with or without the NOD1 796A-allele. This evidence concerns the gene NOD1 and sarcoidosis.