PDGFD and mastitis: This study’s main objective was to investigate the relationship between SNPs in candidate genes (RASGRP1, NFkB, CHL1, MARCH3, PDGFD, MAST3, EPS15L1, C1QTNF3, CD46, COX18, NEURL1, PPIE, and PTX3) and the incidence of mastitis resistance/susceptibility in Holstein and Montbéliarde dairy cows using PCR-DNA sequencing and real time PCR approaches.