PKD1 and hypersensitivity pneumonitis: At 24 h after the single exposure to S. rectivirgula, the levels of alveolitis in PKD1mKO were similar to the levels of alveolitis in PKD1-insufficient mice previously reported (the number of total cells recovered from the BALF from S. rectivirgula-exposed PKD1-insufficient mice and PKD1mKO were approximately 33% and 35%, respectively, of those in S. rectivirgula-exposed WT mice) (57).