Despite the good bioprofile, the first library of compounds reported by these authors (Scheme 13E), which considered pyrimidine derivatives 94a–y, featured better inhibition values against the VEGFR-2 enzyme and MCF-7 breast cancer cells (compare scaffolds 94i, 94l, 94r, and 94t in Scheme 13E and scaffolds 96j and 96l in Scheme 14B), demonstrating poor efficiency of the pyrimidinone central unit. Here, KDR is linked to breast cancer.