HSP90AA1 and interstitial lung disease: We determined a fold change in the protein level of the two heat shock proteins, HSP90 and HSP70, and two ER-resident chaperones, calreticulin and calnexin, in MLE-12 cells expressing SP-CWT and SP-CI73T, before and after exposure to the pharmacologic substances used in ILD therapy: cyclophosphamide, azathioprine, methylprednisolone or hydroxychloroquine (Figure 4A-D, Table 1).