Among the lymphocytes, the percentages of CD3negCD56+ natural killer (NK) cells, CD3negCD19+ B lymphocytes, and CD3+CD8+ CTL were similar between all groups, and only the CD3+CD4+ TH lymphocyte subset showed a relative deficit in both the AIR and RP patients compared to healthy controls (Figure 4A). Here, CD4 is linked to retinitis pigmentosa 1.