A subgroup analysis of all conjunctival samples revealed that ACE2 expression was not only insignificant in healthy conjunctival tissue (all samples 0 TPM) but also in samples of altered conjunctiva such as conjunctival papilloma (one sample with 1.6 TPM), squamous cell carcinoma (all samples with 0.0 TPM), melanoma (one sample with 1.1 TPM) or pterygium (all samples with 0.0 TPM). This evidence concerns the gene ACE2 and squamous cell carcinoma.