Those with detailed descriptions, there are 5 cases of CD4+ T cell-, 7 cases of CD8+ T cell-, and 3 cases of NK cell-associated indolent LPD with minor endoscopic lesions such as erythema/red mucosa, irregular granular/nodular mucosa and even normal mucosa without ulcer/erosion or polypoid/elevated lesions [11, 14–23]. This evidence concerns the gene CD4 and Erythema.