LDLR and infection: Of the five candidate genes tested, a loss-of-infection phenotype was confirmed only with sgRNA targeting Ldlr. To corroborate these results, we generated ΔLdlr single-cell clones in N2a B4galt7 cells and complemented them with full-length Ldlr cDNA encoding mutations in the sgRNA seed-sequence (Supplementary Fig 1c, d).