Another part of this study is to collect the conjunctiva of SLK patients and normal control patients. This part of the clinical study is sent for IRB approval concomitantly. We will collect the conjunctiva of SLK patients when they receive conjunctival resection as the treatment in the following one year. And the normal control conjunctiva will be obtained while the patients come to our hospital for cataract surgery or retinal surgery with redundant conjunctiva noted after peritomy. The fresh conjunctiva will be stored in -80℃ before RNA isolation. All the tissue will be processed into RNA and reverse transcripted into cDNA. Polymerase chain reaction will be done with the primers, including CXCR1, CXCR2, CXCR3, CXCR4, CCR1, CCR3, CCR4, CCR5, and CD30L.