COL4A4 and chronic kidney disease: For example, in CKD we observe that some of the most well-established CKD-associated genes (PKD1, PKD2, COL4A1, COL4A3, COL4A4, and COL4A5) rank in the top nine genes among the 17 known CKD genes that achieved both a collapsing analysis p < 0.05 and hypergeometric test p < 0.05 (Figure S13).