BECN1 and silicosis: Next, Beclin1 expression in the alveolus tissues of early‐stage silicosis (day 3 after CS treatment) was observed to be higher than that in the advanced stage silicosis (56 days after CS treatment), and alveolus tissues of silicosis at both stages presented with upregulated Beclin1 expression relative to normal alveolar tissues (Figure 1C).