NELL1 and renal cell carcinoma: In our model, all 20 genes are involved in human cancer occurrence and development, half of which are closely related to RCC (ADAMTS2 [17], COL15A1 [18], COL4A4 [19], DCN [19], ITGA5 [20], ITGAX [21], MMP7 [22], NELL1 [23], SEMA3B [24], and VCAN [25]).