Total RNA isolated from infected and uninfected HeLa cells was analyzed by quantitative reverse transcription-PCR using primers targeting NFκB1, O. tsutsugamushi 16S rRNA, and GAPDH. O. tsutsugamushi 16S rRNA levels increased only in infected samples over the time course, thereby confirming that the infection proceeded normally (Fig 3G). Here, NFKB1 is linked to infection.