ACE2 and pterygium: 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).