ATP6V1B2 and escherichia coli infection: Further qRT-PCR assays showed that representative genes of phagosome maturation were significantly upregulated in response to E. coli infection including ATP6V1A, ATP6V1B2, BF2, CTSS, and TFRC, while COLEC12 was downregulated at 72 h (Figure S17 and Table S16).